diff --git a/include/cutscenes/boat_cutscene.h b/include/cutscenes/boat_cutscene.h
index 6fe038e727..9e498d3120 100644
--- a/include/cutscenes/boat_cutscene.h
+++ b/include/cutscenes/boat_cutscene.h
@@ -2,6 +2,7 @@
 #define POKEPLATINUM_BOAT_CUTSCENE_H
 
 #include "constants/boat_cutscene.h"
+#include "generated/map_headers.h"
 
 #include "field/field_system_decl.h"
 #include "overlay005/model_attributes.h"
@@ -28,7 +29,7 @@ typedef struct BoatTravelCutscene {
     ModelAttributes *areaModelAttrs;
 } BoatTravelCutscene;
 
-void FieldSystem_PlayBoatCutscene(FieldSystem *fieldSystem, const u8 travelDir, const u8 exitDir, const int mapID, const int x, const int z);
+void FieldSystem_PlayBoatCutscene(FieldSystem *fieldSystem, const u8 travelDir, const u8 exitDir, const enum MapHeaderID mapHeaderID, const int x, const int z);
 
 BOOL BoatCutscene_CanalaveShip_Init(ApplicationManager *appMan, int *state);
 BOOL BoatCutscene_CanalaveShip_Main(ApplicationManager *appMan, int *state);
diff --git a/include/field/field_system.h b/include/field/field_system.h
index beb2208793..d08ee573a7 100644
--- a/include/field/field_system.h
+++ b/include/field/field_system.h
@@ -120,7 +120,7 @@ typedef struct FieldSystem_t {
     BattleTower *battleTower;
     const BattleRegulation *battleRegulation;
     PokedexMemory *pokedexMemory;
-    BOOL unk_B8;
+    BOOL temporaryMapChange;
     u8 *battleSubscreenCursorOn;
     u32 unk_C0;
     UnkStruct_ov66_0222DCE0_sub1 unk_C4;
diff --git a/include/field_bgm.h b/include/field_bgm.h
index 3e9d4b96a0..e1b4ec4c5d 100644
--- a/include/field_bgm.h
+++ b/include/field_bgm.h
@@ -11,12 +11,12 @@ void FieldBGM_Stop(void);
 void FieldBGM_SetOverride(FieldSystem *fieldSystem, u16 bgmID);
 u16 FieldBGM_GetOverride(FieldSystem *fieldSystem);
 void FieldBGM_ClearOverride(FieldSystem *fieldSystem);
-u16 FieldBGM_GetEffective(FieldSystem *fieldSystem, enum MapHeaderID mapID);
-u16 FieldBGM_GetForMapHeader(FieldSystem *fieldSystem, int mapID);
+u16 FieldBGM_GetEffective(FieldSystem *fieldSystem, enum MapHeaderID mapHeaderID);
+u16 FieldBGM_GetForMapHeader(FieldSystem *fieldSystem, enum MapHeaderID mapHeaderID);
 BOOL FieldBGM_TryFadeOut(FieldSystem *fieldSystem, u16 bgmID, int mode);
 u16 FieldBGM_GetEyesMeetForTrainer(enum TrainerID trainerID);
-void FieldBGM_TryFadeIn(FieldSystem *fieldSystem, int mapID);
-void FieldBGM_PlayForMapHeader(FieldSystem *fieldSystem, int mapID);
-void FieldBGM_PlayEffectiveForMapHeader(FieldSystem *fieldSystem, int mapID);
+void FieldBGM_TryFadeIn(FieldSystem *fieldSystem, enum MapHeaderID mapHeaderID);
+void FieldBGM_PlayForMapHeader(FieldSystem *fieldSystem, enum MapHeaderID mapHeaderID);
+void FieldBGM_PlayEffectiveForMapHeader(FieldSystem *fieldSystem, enum MapHeaderID mapHeaderID);
 
 #endif // POKEPLATINUM_FIELD_BGM_H
diff --git a/include/field_map_change.h b/include/field_map_change.h
index ca4c43860e..5f403efecf 100644
--- a/include/field_map_change.h
+++ b/include/field_map_change.h
@@ -1,6 +1,8 @@
 #ifndef POKEPLATINUM_FIELD_MAP_CHANGE_H
 #define POKEPLATINUM_FIELD_MAP_CHANGE_H
 
+#include "generated/map_headers.h"
+
 #include "field/field_system_decl.h"
 #include "overlay005/save_info_window.h"
 #include "overlay006/field_warp.h"
@@ -14,7 +16,7 @@
 typedef struct MapChangeUndergroundContext {
     int state;
     int transitionState;
-    int mapId;
+    enum MapHeaderID mapHeaderID;
     int dummy;
     int destX;
     int destZ;
@@ -36,10 +38,10 @@ void FieldSystem_SetLoadSavedGameMapTask(FieldSystem *fieldSystem);
 void FieldSystem_StartLoadMapFromErrorTask(FieldSystem *fieldSystem);
 void FieldSystem_StartChangeMapTask(FieldTask *task, const Location *param1);
 void FieldTask_ChangeMapByLocation(FieldTask *task, const Location *param1);
-void FieldTask_ChangeMapToLocation(FieldTask *task, int mapId, int warpId, int x, int z, int dir);
-void FieldTask_StartMapChangeFull(FieldTask *task, int mapId, int warpId, int x, int z, int dir);
-void FieldTask_StartMapChangeFly(FieldSystem *fieldSystem, int mapId, int warpId, int x, int z, int dir);
-void FieldTask_ChangeMapChangeFly(FieldTask *task, int mapId, int warpId, int x, int z, int dir);
+void FieldTask_ChangeMapToLocation(FieldTask *task, enum MapHeaderID mapHeaderID, int warpId, int x, int z, int dir);
+void FieldTask_StartMapChangeFull(FieldTask *task, enum MapHeaderID mapHeaderID, int warpId, int x, int z, int dir);
+void FieldTask_StartMapChangeFly(FieldSystem *fieldSystem, enum MapHeaderID mapHeaderID, int warpId, int x, int z, int dir);
+void FieldTask_ChangeMapChangeFly(FieldTask *task, enum MapHeaderID mapHeaderID, int warpId, int x, int z, int dir);
 void FieldTask_ChangeMapByFieldWarp(FieldTask *task, const Location *location, enum FieldWarpType param2);
 void FieldSystem_StartMapChangeWarpTask(FieldSystem *fieldSystem, int param1, int param2);
 MapChangeUndergroundContext *MapChangeUndergroundContext_New(FieldSystem *fieldSystem);
@@ -50,7 +52,7 @@ FieldTaskFunc FieldMapChange_GetMapChangeUndergroundTask(const FieldSystem *fiel
 void sub_020544F0(FieldTask *task, const Location *param1);
 void sub_020545EC(FieldSystem *fieldSystem);
 void sub_02054708(FieldTask *task);
-void FieldTask_StartChangeMapColosseum(FieldTask *task, int mapId, int warpId, int x, int z, int dir);
+void FieldTask_StartChangeMapColosseum(FieldTask *task, enum MapHeaderID mapHeaderID, int warpId, int x, int z, int dir);
 void sub_02054864(FieldTask *task);
 
 #endif // POKEPLATINUM_FIELD_MAP_CHANGE_H
diff --git a/include/unk_02070428.h b/include/field_map_change_flags.h
similarity index 56%
rename from include/unk_02070428.h
rename to include/field_map_change_flags.h
index 30b3c9c286..08f11ba416 100644
--- a/include/unk_02070428.h
+++ b/include/field_map_change_flags.h
@@ -1,15 +1,15 @@
-#ifndef POKEPLATINUM_UNK_02070428_H
-#define POKEPLATINUM_UNK_02070428_H
+#ifndef POKEPLATINUM_FIELD_MAP_CHANGE_FLAGS_H
+#define POKEPLATINUM_FIELD_MAP_CHANGE_FLAGS_H
 
 #include "field/field_system_decl.h"
 
-void sub_02070428(FieldSystem *fieldSystem, BOOL param1);
+void FieldSystem_SetTemporaryMapChange(FieldSystem *fieldSystem, BOOL temporaryMapChange);
 void FieldSystem_InitFlagsOnMapChange(FieldSystem *fieldSystem);
 void FieldSystem_InitFlagsWarp(FieldSystem *fieldSystem);
 void FieldSystem_SetFlyFlags(FieldSystem *fieldSystem);
 void FieldSystem_SetTeleportFlags(FieldSystem *fieldSystem);
 void FieldSystem_SetEscapeFlags(FieldSystem *fieldSystem);
 void FieldSystem_ClearPartnerTrainer(FieldSystem *fieldSystem);
-void sub_020705CC(FieldSystem *fieldSystem);
+void FieldSystem_RandomizeRoamingPokemonLocations(FieldSystem *fieldSystem);
 
-#endif // POKEPLATINUM_UNK_02070428_H
+#endif // POKEPLATINUM_FIELD_MAP_CHANGE_FLAGS_H
diff --git a/include/field_move_tasks.h b/include/field_move_tasks.h
index 843f657763..21c0be3184 100644
--- a/include/field_move_tasks.h
+++ b/include/field_move_tasks.h
@@ -1,6 +1,8 @@
 #ifndef POKEPLATINUM_FIELD_MOVE_TASKS_H
 #define POKEPLATINUM_FIELD_MOVE_TASKS_H
 
+#include "generated/map_headers.h"
+
 #include "struct_decls/map_object.h"
 
 #include "field/field_system_decl.h"
@@ -9,7 +11,7 @@
 #include "pokemon.h"
 
 typedef struct FieldMoveContext {
-    u32 mapId;
+    enum MapHeaderID mapHeaderID;
     FieldSystem *fieldSystem;
     MapObject *mapObj;
     u16 usableMoves;
diff --git a/include/inlines.h b/include/inlines.h
index 3962b9822f..3cec373efe 100644
--- a/include/inlines.h
+++ b/include/inlines.h
@@ -130,7 +130,7 @@ static inline void PoketchMap_GetPlayerLocation(FieldSystem *fieldSystem, int *x
     FieldOverworldState *fieldState = SaveData_GetFieldOverworldState(fieldSystem->saveData);
     Location *location = FieldOverworldState_GetExitLocation(fieldState);
 
-    if (MapHeader_IsOnMainMatrix(fieldSystem->location->mapId)) {
+    if (MapHeader_IsOnMainMatrix(fieldSystem->location->mapHeaderID)) {
         *x = fieldSystem->location->x;
         *z = fieldSystem->location->z;
     } else {
diff --git a/include/location.h b/include/location.h
index de66846da8..1b7f5a992b 100644
--- a/include/location.h
+++ b/include/location.h
@@ -1,6 +1,8 @@
 #ifndef POKEPLATINUM_LOCATION_H
 #define POKEPLATINUM_LOCATION_H
 
+#include "generated/map_headers.h"
+
 #include "savedata.h"
 
 #define WARP_ID_NONE -1
@@ -14,16 +16,16 @@ enum FaceDirection {
 };
 
 typedef struct Location {
-    int mapId;
+    enum MapHeaderID mapHeaderID;
     int warpId;
     int x;
     int z;
     int faceDirection;
 } Location;
 
-static inline void Location_Set(Location *location, int mapId, int warpId, int x, int z, int faceDirection)
+static inline void Location_Set(Location *location, enum MapHeaderID mapHeaderID, int warpId, int x, int z, int faceDirection)
 {
-    location->mapId = mapId;
+    location->mapHeaderID = mapHeaderID;
     location->warpId = warpId;
     location->x = x;
     location->z = z;
diff --git a/include/map_header.h b/include/map_header.h
index b1285215de..e59447fba7 100644
--- a/include/map_header.h
+++ b/include/map_header.h
@@ -3,6 +3,7 @@
 
 #include "generated/battle_backgrounds.h"
 #include "generated/evolution_methods.h"
+#include "generated/map_headers.h"
 
 #define ENCOUNTERS_NONE 0xFFFF
 
@@ -29,40 +30,40 @@ typedef struct MapHeader {
     u16 isFlyAllowed : 1;
 } MapHeader;
 
-u32 MapHeader_IDBoundsCheck(u32 headerID);
-u16 MapHeader_GetAreaDataArchiveID(u32 headerID);
-u16 MapHeader_GetPreloadedMapObjectsArchiveID(u32 headerID);
-u16 MapHeader_GetMapMatrixID(u32 headerID);
-u32 MapHeader_GetMsgArchiveID(u32 headerID);
-u32 MapHeader_GetScriptsArchiveID(u32 headerID);
-u32 MapHeader_GetInitScriptsArchiveID(u32 headerID);
-u16 MapHeader_GetDayMusicID(u32 headerID);
-u16 MapHeader_GetNightMusicID(u32 headerID);
-BOOL MapHeader_HasWildEncounters(u32 headerID);
-u32 MapHeader_GetWildEncountersArchiveID(u32 headerID);
-u32 MapHeader_GetEventsArchiveID(u32 headerID);
-u32 MapHeader_GetMapLabelTextID(u32 headerID);
-u8 MapHeader_GetMapLabelWindowID(u32 headerID);
-u32 MapHeader_GetWeatherType(u32 headerID);
-u32 MapHeader_GetCameraType(u32 headerID);
-enum BattleBackground MapHeader_GetBattleBG(u32 headerID);
-BOOL MapHeader_IsEscapeRopeAllowed(u32 headerID);
-BOOL MapHeader_IsFlyAllowed(u32 headerID);
-BOOL MapHeader_IsBikeAllowed(u32 headerID);
-u32 MapHeader_GetMapType(u32 headerID);
-BOOL MapHeader_IsTeleportAllowed(u32 headerID);
-BOOL MapHeader_IsOnMainMatrix(u32 headerID);
-BOOL MapHeader_IsPokemonCenter(u32 headerID);
-BOOL MapHeader_IsCave(u32 headerID);
-BOOL MapHeader_IsBuilding(u32 headerID);
-BOOL MapHeader_IsOutdoors(u32 headerID);
-BOOL MapHeader_IsPokemonCenter2(u32 headerID);
-BOOL MapHeader_IsUnionRoom(const u32 headerID);
-BOOL MapHeader_HasFeebasTiles(const u32 headerID);
-BOOL MapHeader_IsTrophyGarden(const u32 headerID);
-BOOL MapHeader_IsAmitySquare(const u32 headerID);
-BOOL MapHeader_IsAzureFluteAllowed(const u32 headerID);
-BOOL MapHeader_IsPokemonCenter2F(const u32 headerID);
-enum EvolutionMethod MapHeader_GetMapEvolutionMethod(u32 headerID);
+enum MapHeaderID MapHeader_IDBoundsCheck(enum MapHeaderID mapHeaderID);
+u16 MapHeader_GetAreaDataArchiveID(enum MapHeaderID mapHeaderID);
+u16 MapHeader_GetPreloadedMapObjectsArchiveID(enum MapHeaderID mapHeaderID);
+u16 MapHeader_GetMapMatrixID(enum MapHeaderID mapHeaderID);
+u32 MapHeader_GetMsgArchiveID(enum MapHeaderID mapHeaderID);
+u32 MapHeader_GetScriptsArchiveID(enum MapHeaderID mapHeaderID);
+u32 MapHeader_GetInitScriptsArchiveID(enum MapHeaderID mapHeaderID);
+u16 MapHeader_GetDayMusicID(enum MapHeaderID mapHeaderID);
+u16 MapHeader_GetNightMusicID(enum MapHeaderID mapHeaderID);
+BOOL MapHeader_HasWildEncounters(enum MapHeaderID mapHeaderID);
+u32 MapHeader_GetWildEncountersArchiveID(enum MapHeaderID mapHeaderID);
+u32 MapHeader_GetEventsArchiveID(enum MapHeaderID mapHeaderID);
+u32 MapHeader_GetMapLabelTextID(enum MapHeaderID mapHeaderID);
+u8 MapHeader_GetMapLabelWindowID(enum MapHeaderID mapHeaderID);
+u32 MapHeader_GetWeatherType(enum MapHeaderID mapHeaderID);
+u32 MapHeader_GetCameraType(enum MapHeaderID mapHeaderID);
+enum BattleBackground MapHeader_GetBattleBG(enum MapHeaderID mapHeaderID);
+BOOL MapHeader_IsEscapeRopeAllowed(enum MapHeaderID mapHeaderID);
+BOOL MapHeader_IsFlyAllowed(enum MapHeaderID mapHeaderID);
+BOOL MapHeader_IsBikeAllowed(enum MapHeaderID mapHeaderID);
+u32 MapHeader_GetMapType(enum MapHeaderID mapHeaderID);
+BOOL MapHeader_IsTeleportAllowed(enum MapHeaderID mapHeaderID);
+BOOL MapHeader_IsOnMainMatrix(enum MapHeaderID mapHeaderID);
+BOOL MapHeader_IsPokemonCenter(enum MapHeaderID mapHeaderID);
+BOOL MapHeader_IsCave(enum MapHeaderID mapHeaderID);
+BOOL MapHeader_IsBuilding(enum MapHeaderID mapHeaderID);
+BOOL MapHeader_IsOutdoors(enum MapHeaderID mapHeaderID);
+BOOL MapHeader_IsPokemonCenter2(enum MapHeaderID mapHeaderID);
+BOOL MapHeader_IsUnionRoom(const enum MapHeaderID mapHeaderID);
+BOOL MapHeader_HasFeebasTiles(const enum MapHeaderID mapHeaderID);
+BOOL MapHeader_IsTrophyGarden(const enum MapHeaderID mapHeaderID);
+BOOL MapHeader_IsAmitySquare(const enum MapHeaderID mapHeaderID);
+BOOL MapHeader_IsAzureFluteAllowed(const enum MapHeaderID mapHeaderID);
+BOOL MapHeader_IsPokemonCenter2F(const enum MapHeaderID mapHeaderID);
+enum EvolutionMethod MapHeader_GetMapEvolutionMethod(enum MapHeaderID mapHeaderID);
 
 #endif // POKEPLATINUM_MAP_HEADER_H
diff --git a/include/map_header_data.h b/include/map_header_data.h
index b53314de41..40974f5578 100644
--- a/include/map_header_data.h
+++ b/include/map_header_data.h
@@ -2,6 +2,7 @@
 #define POKEPLATINUM_MAP_HEADER_DATA_H
 
 #include "constants/heap.h"
+#include "generated/map_headers.h"
 
 #include "field/field_system_decl.h"
 #include "overlay006/wild_encounters.h"
@@ -67,7 +68,7 @@ typedef struct MapHeaderData {
 
 void MapHeaderData_Init(FieldSystem *fieldSystem, enum HeapID heapID);
 void MapHeaderData_Free(FieldSystem *fieldSystem);
-void MapHeaderData_Load(FieldSystem *fieldSystem, int headerID);
+void MapHeaderData_Load(FieldSystem *fieldSystem, enum MapHeaderID mapHeaderID);
 void sub_0203A418(FieldSystem *fieldSystem);
 const BgEvent *MapHeaderData_GetBgEvents(const FieldSystem *fieldSystem);
 int MapHeaderData_GetNumBgEvents(const FieldSystem *fieldSystem);
@@ -84,7 +85,7 @@ BOOL MapHeaderData_SetWarpEventPos(FieldSystem *fieldSystem, u16 index, u16 x, u
 BOOL MapHeaderData_SetWarpEventDestHeaderID(FieldSystem *fieldSystem, u16 index, u16 destHeaderID);
 BOOL MapHeaderData_SetWarpEventDestWarpID(FieldSystem *fieldSystem, u16 index, u16 destWarpID);
 BOOL MapHeaderData_SetBgEventPos(FieldSystem *fieldSystem, u16 index, u16 x, u16 z);
-void MapHeaderData_LoadWildEncounters(WildEncounters *encounterData, int headerID);
+void MapHeaderData_LoadWildEncounters(WildEncounters *data, enum MapHeaderID mapHeaderID);
 const WildEncounters *MapHeaderData_GetWildEncounters(const FieldSystem *fieldSystem);
 const u8 *MapHeaderData_GetInitScriptBytes(const FieldSystem *fieldSystem);
 BOOL MapHeaderData_IsPosFreeOfObjectEvents(const FieldSystem *fieldSystem, u16 x, u16 z);
diff --git a/include/map_object.h b/include/map_object.h
index 895f95b1d0..2283330c7c 100644
--- a/include/map_object.h
+++ b/include/map_object.h
@@ -5,6 +5,7 @@
 
 #include "constants/field/map.h"
 #include "constants/map_object.h"
+#include "generated/map_headers.h"
 #include "generated/movement_actions.h"
 
 #include "struct_decls/map_object.h"
@@ -60,10 +61,10 @@ typedef struct MapObjectSave {
 
 MapObjectManager *MapObjectMan_New(FieldSystem *fieldSystem, int maxObjs, int taskBasePriority);
 void MapObjectMan_Delete(MapObjectManager *mapObjMan);
-void sub_0206184C(MapObjectManager *mapObjMan, int mapID, int param2, int objEventCount, const ObjectEvent *objectEvent);
-MapObject *MapObjectMan_AddMapObjectFromHeader(const MapObjectManager *mapObjMan, const ObjectEvent *objectEvent, int mapID);
-MapObject *MapObjectMan_AddMapObject(const MapObjectManager *mapObjMan, int x, int z, int initialDir, int graphicsID, int movementType, int mapID);
-MapObject *MapObjectMan_AddMapObjectFromLocalID(const MapObjectManager *mapObjMan, int param1, int objEventCount, int mapID, const ObjectEvent *objectEvent);
+void sub_0206184C(MapObjectManager *mapObjMan, enum MapHeaderID oldMapHeaderID, enum MapHeaderID newMapHeaderID, int objEventCount, const ObjectEvent *objectEvent);
+MapObject *MapObjectMan_AddMapObjectFromHeader(const MapObjectManager *mapObjMan, const ObjectEvent *objectEvent, enum MapHeaderID mapHeaderID);
+MapObject *MapObjectMan_AddMapObject(const MapObjectManager *mapObjMan, int x, int z, int initialDir, int graphicsID, int movementType, enum MapHeaderID mapHeaderID);
+MapObject *MapObjectMan_AddMapObjectFromLocalID(const MapObjectManager *mapObjMan, int param1, int objEventCount, enum MapHeaderID mapHeaderID, const ObjectEvent *objectEvent);
 void sub_02061AB4(MapObject *mapObj, int graphicsID);
 void sub_02061AD4(MapObject *mapObj, int param1);
 void MapObject_Delete(MapObject *mapObj);
@@ -74,14 +75,14 @@ void sub_02061BF0(MapObjectManager *mapObjMan);
 void sub_02061C48(MapObjectManager *mapObjMan);
 void MapObjectMan_SaveAll(FieldSystem *fieldSystem, const MapObjectManager *mapObjMan, MapObjectSave *mapObjSave, int param3);
 void MapObjectMan_LoadAllObjects(const MapObjectManager *mapObjMan, MapObjectSave *mapObjSave, int size);
-void sub_02062068(const MapObjectManager *mapObjMan, int param1, int param2, const ObjectEvent *objectEvent);
+void sub_02062068(const MapObjectManager *mapObjMan, enum MapHeaderID mapHeaderID, u32 numObjectEvents, const ObjectEvent *objectEvent);
 MapObject *MapObjMan_LocalMapObjByIndex(const MapObjectManager *mapObjMan, int index);
 MapObject *MapObjMan_GetLocalMapObjByMovementType(const MapObjectManager *mapObjMan, int movementType);
 BOOL MapObjectMan_FindObjectWithStatus(const MapObjectManager *mapObjMan, MapObject **mapObj, int *startIdx, u32 status);
 int MapObject_HasNoScript(const MapObject *mapObj);
 int MapObject_CalculateTaskPriority(const MapObject *mapObj, int priority);
-int sub_02062764(const MapObject *mapObj, int param1, int param2);
-int sub_020627B4(const MapObject *mapObj, int param1, int param2, int param3);
+int sub_02062764(const MapObject *mapObj, int param1, enum MapHeaderID param2);
+int sub_020627B4(const MapObject *mapObj, int param1, int param2, enum MapHeaderID param3);
 void MapObjectMan_SetMaxObjects(MapObjectManager *mapObjMan, int maxObjs);
 int MapObjectMan_GetMaxObjects(const MapObjectManager *mapObjMan);
 void MapObjectMan_SetStatusFlagOn(MapObjectManager *mapObjMan, u32 flag);
@@ -111,8 +112,8 @@ void sub_020628F8(MapObject *mapObj, u32 param1);
 u32 sub_02062904(const MapObject *mapObj, u32 param1);
 void MapObject_SetLocalID(MapObject *mapObj, u32 localID);
 u32 MapObject_GetLocalID(const MapObject *mapObj);
-void MapObject_SetMapID(MapObject *mapObj, int mapID);
-int MapObject_GetMapID(const MapObject *mapObj);
+void MapObject_SetMapHeaderID(MapObject *mapObj, enum MapHeaderID mapHeaderID);
+enum MapHeaderID MapObject_GetMapHeaderID(const MapObject *mapObj);
 void MapObject_SetGraphicsID(MapObject *mapObj, u32 graphicsID);
 u32 MapObject_GetGraphicsID(const MapObject *mapObj);
 u32 MapObject_GetEffectiveGraphicsID(const MapObject *mapObj);
diff --git a/include/overlay005/fieldmap.h b/include/overlay005/fieldmap.h
index c968ebd668..871f8a24a9 100644
--- a/include/overlay005/fieldmap.h
+++ b/include/overlay005/fieldmap.h
@@ -1,6 +1,8 @@
 #ifndef POKEPLATINUM_OV5_021D0D80_H
 #define POKEPLATINUM_OV5_021D0D80_H
 
+#include "generated/map_headers.h"
+
 #include "field/field_system_decl.h"
 
 #include "bg_window.h"
@@ -8,7 +10,7 @@
 
 extern const ApplicationManagerTemplate gFieldMapTemplate;
 
-void FieldMap_ChangeZoneDistortionWorld(FieldSystem *fieldSystem, u32 mapId);
+void FieldMap_ChangeZoneDistortionWorld(FieldSystem *fieldSystem, enum MapHeaderID mapHeaderID);
 void ov5_021D1434(BgConfig *param0);
 void ov5_021D143C(BgConfig *param0);
 void ov5_021D16F4(FieldSystem *fieldSystem, BOOL param1);
diff --git a/include/overlay006/great_marsh_binoculars.h b/include/overlay006/great_marsh_binoculars.h
index 98ba675e72..fbf68c1c04 100644
--- a/include/overlay006/great_marsh_binoculars.h
+++ b/include/overlay006/great_marsh_binoculars.h
@@ -1,6 +1,8 @@
 #ifndef POKEPLATINUM_GREAT_MARSH_BINOCULARS_H
 #define POKEPLATINUM_GREAT_MARSH_BINOCULARS_H
 
+#include "generated/map_headers.h"
+
 #include "field/field_system_decl.h"
 
 #include "great_marsh_lookout.h"
@@ -16,7 +18,7 @@ typedef struct GreatMarshBinoculars {
     BinocularCoords coordsList[BINOCULARS_CYCLE_COUNT + 1];
     Location viewLocation;
     FieldSystem *fieldSystem;
-    int lookoutMapId;
+    enum MapHeaderID lookoutMapHeaderID;
 } GreatMarshBinoculars;
 
 int GreatMarshBinoculars_GetMonSpecies(FieldSystem *fieldSystem);
diff --git a/include/overlay006/great_marsh_daily_encounters.h b/include/overlay006/great_marsh_daily_encounters.h
index 9089e7104e..33d528a56f 100644
--- a/include/overlay006/great_marsh_daily_encounters.h
+++ b/include/overlay006/great_marsh_daily_encounters.h
@@ -1,6 +1,8 @@
 #ifndef POKEPLATINUM_MARSH_DAILY_ENCOUNTERS_H
 #define POKEPLATINUM_MARSH_DAILY_ENCOUNTERS_H
 
-void ReplaceGreatMarshDailyEncounters(const int dailyMon, const BOOL nationalDexObtained, const int mapId, int *encounterSlot1, int *encounterSlot2);
+#include "generated/map_headers.h"
+
+void ReplaceGreatMarshDailyEncounters(const int dailyMon, const BOOL nationalDexObtained, const enum MapHeaderID mapHeaderID, int *encounterSlot1, int *encounterSlot2);
 
 #endif // POKEPLATINUM_MARSH_DAILY_ENCOUNTERS_H
diff --git a/include/spawn_locations.h b/include/spawn_locations.h
index 9c59b5330c..9c5433f240 100644
--- a/include/spawn_locations.h
+++ b/include/spawn_locations.h
@@ -1,6 +1,8 @@
 #ifndef POKEPLATINUM_SPAWN_LOCATIONS_H
 #define POKEPLATINUM_SPAWN_LOCATIONS_H
 
+#include "generated/map_headers.h"
+
 #include "field/field_system_decl.h"
 
 #include "location.h"
@@ -8,10 +10,10 @@
 int FieldOverworldState_GetDefaultWarpID(void);
 void Location_InitFly(int flyDestination, Location *location);
 void Location_InitBlackOut(int blackOutDestination, Location *location);
-int GetMapBlackOutWarpId(int mapId);
-int GetMapFlyWarpId(int mapId);
-int GetSpawnIdByMapAndCoords(int mapID, int param1, int param2);
-void TryUnlockFlyLocationByMap(FieldSystem *fieldSystem, int param1);
-BOOL CheckFlyLocationUnlocked(FieldSystem *fieldSystem, int param1);
+int GetMapBlackOutWarpId(enum MapHeaderID mapHeaderID);
+int GetMapFlyWarpId(enum MapHeaderID mapHeaderID);
+int GetSpawnIdByMapAndCoords(enum MapHeaderID mapHeaderID, int param1, int param2);
+void TryUnlockFlyLocationByMap(FieldSystem *fieldSystem, enum MapHeaderID mapHeaderID);
+BOOL CheckFlyLocationUnlocked(FieldSystem *fieldSystem, int flyLocation);
 
 #endif // POKEPLATINUM_SPAWN_LOCATIONS_H
diff --git a/platinum.us/main.lsf b/platinum.us/main.lsf
index 00f99d0c31..020a65d8e4 100644
--- a/platinum.us/main.lsf
+++ b/platinum.us/main.lsf
@@ -276,7 +276,7 @@ Static main
 	Object main.nef.p/src_cutscenes_boat_cutscene_boat_cutscene.c.o
 	Object main.nef.p/src_tv_segment.c.o
 	Object main.nef.p/src_rankings_machine.c.o
-	Object main.nef.p/src_unk_02070428.c.o
+	Object main.nef.p/src_field_map_change_flags.c.o
 	Object main.nef.p/src_field_move_tasks.c.o
 	Object main.nef.p/src_unk_020711C8.c.o
 	Object main.nef.p/src_overworld_anim_manager.c.o
diff --git a/src/applications/party_menu/callbacks.c b/src/applications/party_menu/callbacks.c
index 9b7e4d46c8..81afc06387 100644
--- a/src/applications/party_menu/callbacks.c
+++ b/src/applications/party_menu/callbacks.c
@@ -815,7 +815,7 @@ static enum PartyMenuState PartyMenuCB_LevelUp(PartyMenuApplication *application
 
     case LEVELUP_STATE_CHECK_EVOLUTION:
         mon = Party_GetPokemonBySlotIndex(application->partyMenu->party, application->currPartySlot);
-        u32 mapEvoMethod = MapHeader_GetMapEvolutionMethod(application->partyMenu->fieldSystem->location->mapId);
+        u32 mapEvoMethod = MapHeader_GetMapEvolutionMethod(application->partyMenu->fieldSystem->location->mapHeaderID);
         application->partyMenu->evoTargetSpecies = Pokemon_GetEvolutionTargetSpecies(
             application->partyMenu->party,
             mon,
@@ -1238,5 +1238,5 @@ void PartyMenu_GiveMail(PartyMenuApplication *application)
 static u16 GetCurrentMapLabel(PartyMenuApplication *application)
 {
     FieldSystem *fieldSystem = application->partyMenu->fieldSystem;
-    return MapHeader_GetMapLabelTextID(fieldSystem->location->mapId);
+    return MapHeader_GetMapLabelTextID(fieldSystem->location->mapHeaderID);
 }
diff --git a/src/applications/party_menu/main.c b/src/applications/party_menu/main.c
index a634a34715..98d88de6e1 100644
--- a/src/applications/party_menu/main.c
+++ b/src/applications/party_menu/main.c
@@ -2757,7 +2757,7 @@ static int ProcessItemApplication(PartyMenuApplication *application)
             StringTemplate_Format(application->template, application->tmpString, application->tmpFormat);
             v2 = PARTY_MENU_STATE_CONFIRM_ITEM_UPDATE;
         } else if (fieldSystem != NULL) {
-            if (fieldSystem->location->mapId == MAP_HEADER_UNION_ROOM) {
+            if (fieldSystem->location->mapHeaderID == MAP_HEADER_UNION_ROOM) {
                 MessageLoader_GetString(application->messageLoader, PartyMenu_Text_ItemCannotBeGivenHere, application->tmpFormat);
                 StringTemplate_SetItemName(application->template, 0, application->partyMenu->usedItemID);
                 StringTemplate_Format(application->template, application->tmpString, application->tmpFormat);
@@ -2812,8 +2812,8 @@ static int UpdatePokemonWithItem(PartyMenuApplication *application, Pokemon *mon
     Pokemon_SetArceusForm(mon);
 
     if (fieldSystem == NULL
-        || fieldSystem->location->mapId < MAP_HEADER_DISTORTION_WORLD_1F
-        || (fieldSystem->location->mapId > MAP_HEADER_DISTORTION_WORLD_TURNBACK_CAVE_ROOM)) {
+        || fieldSystem->location->mapHeaderID < MAP_HEADER_DISTORTION_WORLD_1F
+        || (fieldSystem->location->mapHeaderID > MAP_HEADER_DISTORTION_WORLD_TURNBACK_CAVE_ROOM)) {
         *param2 = Pokemon_SetGiratinaFormByHeldItem(mon);
     } else {
         *param2 = -1;
diff --git a/src/applications/party_menu/unk_02083370.c b/src/applications/party_menu/unk_02083370.c
index ae01ffecaf..0c36f23705 100644
--- a/src/applications/party_menu/unk_02083370.c
+++ b/src/applications/party_menu/unk_02083370.c
@@ -230,8 +230,8 @@ static void PartyMenu_SelectItemTake(PartyMenuApplication *application, int *par
         Pokemon_SetArceusForm(mon);
 
         if (fieldSystem == NULL
-            || fieldSystem->location->mapId < MAP_HEADER_DISTORTION_WORLD_1F
-            || fieldSystem->location->mapId > MAP_HEADER_DISTORTION_WORLD_TURNBACK_CAVE_ROOM) {
+            || fieldSystem->location->mapHeaderID < MAP_HEADER_DISTORTION_WORLD_1F
+            || fieldSystem->location->mapHeaderID > MAP_HEADER_DISTORTION_WORLD_TURNBACK_CAVE_ROOM) {
             v1 = Pokemon_SetGiratinaFormByHeldItem(mon);
 
             if ((application->partyMembers[application->currPartySlot].heldItem == ITEM_GRISEOUS_ORB) && (v1 == 0)) {
diff --git a/src/applications/poketch/link_searcher/main.c b/src/applications/poketch/link_searcher/main.c
index 1b03ed560c..99e8bb7b8b 100644
--- a/src/applications/poketch/link_searcher/main.c
+++ b/src/applications/poketch/link_searcher/main.c
@@ -186,7 +186,7 @@ static BOOL State_OnIntroScreen(PoketchLinkSearcher *appData)
 
             PoketchLinkSearcherGraphics_StartTask(appData->graphics, LINK_SEARCHER_GRAPHICS_SEARCHING);
 
-            if (MapHeader_IsPokemonCenter2(fieldSystem->location->mapId)) {
+            if (MapHeader_IsPokemonCenter2(fieldSystem->location->mapHeaderID)) {
                 ChangeState(appData, STATE_UNUSABLE_ERROR);
             } else {
                 ChangeState(appData, STATE_SHOW_RESULTS);
diff --git a/src/applications/town_map/context.c b/src/applications/town_map/context.c
index 0d430ade23..610b9e8b90 100644
--- a/src/applications/town_map/context.c
+++ b/src/applications/town_map/context.c
@@ -93,7 +93,7 @@ void TownMapContext_Init(FieldSystem *fieldSystem, TownMapContext *ctx, enum Tow
     int j = NELEMS(sDistWorldMapOffsets) - 1;
     Location *playerLocation = FieldOverworldState_GetPlayerLocation(fieldState);
 
-    currentMap = playerLocation->mapId;
+    currentMap = playerLocation->mapHeaderID;
 
     while (j >= 0) {
         if (currentMap == sDistWorldMapOffsets[j].mapHeader) {
diff --git a/src/battle_frontier.c b/src/battle_frontier.c
index 6e3f31ca49..27e6992b6a 100644
--- a/src/battle_frontier.c
+++ b/src/battle_frontier.c
@@ -313,7 +313,7 @@ FieldFrontierDTO *sub_0209BA18(FieldSystem *fieldSystem, void *param1)
     fieldData->subscreenCursorOn = fieldSystem->battleSubscreenCursorOn;
     fieldData->unk_14 = 0;
     fieldData->unk_18 = 0;
-    fieldData->mapHeaderID = fieldSystem->location->mapId;
+    fieldData->mapHeaderID = fieldSystem->location->mapHeaderID;
     fieldData->sceneID = FRONTIER_SCENE_14;
     fieldData->fieldSystem = fieldSystem;
 
diff --git a/src/binoculars_vista_lighthouse.c b/src/binoculars_vista_lighthouse.c
index fe268f38f1..76f934ef6e 100644
--- a/src/binoculars_vista_lighthouse.c
+++ b/src/binoculars_vista_lighthouse.c
@@ -10,6 +10,7 @@
 
 #include "camera.h"
 #include "field_map_change.h"
+#include "field_map_change_flags.h"
 #include "field_task.h"
 #include "field_transition.h"
 #include "heap.h"
@@ -21,7 +22,6 @@
 #include "system.h"
 #include "system_flags.h"
 #include "unk_02056B30.h"
-#include "unk_02070428.h"
 #include "vars_flags.h"
 
 typedef struct VistaLighthouseBinoculars {
@@ -54,7 +54,7 @@ static BOOL Task_UseVistaLighthouseBinoculars(FieldTask *taskMan)
     case 0:
         binoculars->xPos = PlayerAvatar_GetXPos(fieldSystem->playerAvatar);
         binoculars->zPos = PlayerAvatar_GetZPos(fieldSystem->playerAvatar);
-        sub_02070428(fieldSystem, 1);
+        FieldSystem_SetTemporaryMapChange(fieldSystem, TRUE);
         FieldTransition_FadeOut(taskMan);
         binoculars->state++;
         break;
@@ -116,7 +116,7 @@ static BOOL Task_UseVistaLighthouseBinoculars(FieldTask *taskMan)
         break;
     case 11:
         Heap_Free(binoculars);
-        sub_02070428(fieldSystem, 0);
+        FieldSystem_SetTemporaryMapChange(fieldSystem, FALSE);
         return TRUE;
     }
 
diff --git a/src/cutscenes/boat_cutscene/boat_cutscene.c b/src/cutscenes/boat_cutscene/boat_cutscene.c
index e0db90d061..f49b380964 100644
--- a/src/cutscenes/boat_cutscene/boat_cutscene.c
+++ b/src/cutscenes/boat_cutscene/boat_cutscene.c
@@ -54,7 +54,7 @@ typedef struct BoatCutscene {
     int goalDistance;
     fx32 bridgeDistance;
     fx32 distanceTraveled;
-    int mapID;
+    enum MapHeaderID mapHeaderID;
     int x;
     int z;
     VecFx32 cameraPos;
@@ -71,25 +71,22 @@ static BOOL BoatCutscene_CheckBridgeReached(const fx32 *distanceTraveled, const
 static void FieldSystem_LoadCanalaveBridgeAnimation(FieldSystem *fieldSystem);
 static void BoatCutscene_PanStartingCamera(BoatCutscene *boatCutscene);
 
-void FieldSystem_PlayBoatCutscene(FieldSystem *fieldSystem, const u8 travelDir, const u8 exitDir, const int mapID, const int x, const int z)
+void FieldSystem_PlayBoatCutscene(FieldSystem *fieldSystem, const u8 travelDir, const u8 exitDir, const enum MapHeaderID mapHeaderID, const int x, const int z)
 {
-    BoatCutscene *boatCutscene;
-    BOOL moveBeforeFadeOut;
-    BOOL boatFound;
     TerrainCollisionHitbox hitbox;
     int targetMapPropModelID;
     int goalDistance;
 
-    boatCutscene = Heap_AllocAtEnd(HEAP_ID_FIELD2, sizeof(BoatCutscene));
+    BoatCutscene *boatCutscene = Heap_AllocAtEnd(HEAP_ID_FIELD2, sizeof(BoatCutscene));
 
     boatCutscene->travelDir = travelDir;
     boatCutscene->exitDir = exitDir;
-    boatCutscene->mapID = mapID;
+    boatCutscene->mapHeaderID = mapHeaderID;
     boatCutscene->x = x;
     boatCutscene->z = z;
     boatCutscene->areaModelAttrs = *(fieldSystem->areaModelAttrs);
 
-    moveBeforeFadeOut = FALSE;
+    BOOL moveBeforeFadeOut = FALSE;
 
     boatCutscene->bridgeDistance = 0xffffffff;
     boatCutscene->dummy = 0;
@@ -111,7 +108,7 @@ void FieldSystem_PlayBoatCutscene(FieldSystem *fieldSystem, const u8 travelDir,
     }
 
     if (moveBeforeFadeOut) {
-        boatFound = FieldSystem_FindCollidingLoadedMapPropByModelID(fieldSystem, targetMapPropModelID, &hitbox, &boatCutscene->boat);
+        BOOL boatFound = FieldSystem_FindCollidingLoadedMapPropByModelID(fieldSystem, targetMapPropModelID, &hitbox, &boatCutscene->boat);
 
         if (boatFound) {
             boatCutscene->goalDistance = goalDistance;
@@ -236,11 +233,11 @@ static BOOL FieldSystem_PlayBoatCutsceneStep(FieldTask *taskMan)
         boatCutscene->state = BOAT_CUTSCENE_STATE_MAP_TRANSITION;
         break;
     case BOAT_CUTSCENE_STATE_MAP_TRANSITION:
-        FieldTask_ChangeMapToLocation(taskMan, boatCutscene->mapID, -1, boatCutscene->x, boatCutscene->z, boatCutscene->exitDir);
+        FieldTask_ChangeMapToLocation(taskMan, boatCutscene->mapHeaderID, -1, boatCutscene->x, boatCutscene->z, boatCutscene->exitDir);
         boatCutscene->state = BOAT_CUTSCENE_STATE_FADE_IN;
         break;
     case BOAT_CUTSCENE_STATE_FADE_IN:
-        FieldBGM_PlayForMapHeader(fieldSystem, boatCutscene->mapID);
+        FieldBGM_PlayForMapHeader(fieldSystem, boatCutscene->mapHeaderID);
         FieldTransition_StartMapAndFadeIn(taskMan);
         boatCutscene->state = BOAT_CUTSCENE_STATE_CLEAN_UP;
         break;
diff --git a/src/dynamic_map_features.c b/src/dynamic_map_features.c
index afbf42107f..ac2a877c7b 100644
--- a/src/dynamic_map_features.c
+++ b/src/dynamic_map_features.c
@@ -104,6 +104,6 @@ BOOL DynamicMapFeatures_CheckCollision(FieldSystem *fieldSystem, const int tileX
 
 BOOL DynamicMapFeatures_WillPlayerJumpEternaGymClock(FieldSystem *fieldSystem, const int tileX, const int tileZ, const fx32 unused3, int direction)
 {
-    return fieldSystem->location->mapId == MAP_HEADER_ETERNA_CITY_GYM
+    return fieldSystem->location->mapHeaderID == MAP_HEADER_ETERNA_CITY_GYM
         && EternaGym_IsHourHandJumpTile(fieldSystem, tileX, tileZ, direction);
 }
diff --git a/src/egg_hatch.c b/src/egg_hatch.c
index e555d0eaf2..9d2a5e2fa8 100644
--- a/src/egg_hatch.c
+++ b/src/egg_hatch.c
@@ -191,7 +191,7 @@ static BOOL FieldTask_HatchEgg(FieldTask *fieldTask)
 
         Pokemon *mon = app->args.mon;
         TrainerInfo *trainerInfo = SaveData_GetTrainerInfo(FieldSystem_GetSaveData(fieldSystem));
-        int location = MapHeader_GetMapLabelTextID(fieldSystem->location->mapId);
+        int location = MapHeader_GetMapLabelTextID(fieldSystem->location->mapHeaderID);
         int isEgg = FALSE;
 
         Pokemon_SetValue(mon, MON_DATA_IS_EGG, &isEgg);
diff --git a/src/encounter.c b/src/encounter.c
index 8e3bad56ad..3379c2f404 100644
--- a/src/encounter.c
+++ b/src/encounter.c
@@ -743,8 +743,8 @@ void Encounter_NewVsTrainer(FieldTask *taskMan, int enemyTrainer1ID, int enemyTr
     dto = FieldBattleDTO_New(HEAP_ID_FIELD2, battleType);
     FieldBattleDTO_Init(dto, fieldSystem);
 
-    if (fieldSystem->location->mapId >= MAP_HEADER_DISTORTION_WORLD_1F
-        && fieldSystem->location->mapId <= MAP_HEADER_DISTORTION_WORLD_TURNBACK_CAVE_ROOM) {
+    if (fieldSystem->location->mapHeaderID >= MAP_HEADER_DISTORTION_WORLD_1F
+        && fieldSystem->location->mapHeaderID <= MAP_HEADER_DISTORTION_WORLD_TURNBACK_CAVE_ROOM) {
         dto->battleStatusMask |= BATTLE_STATUS_DISTORTION;
     }
 
@@ -962,7 +962,7 @@ static void UpdateJournal(FieldSystem *fieldSystem, FieldBattleDTO *dto)
         }
     } else if ((battleType & BATTLE_TYPE_TRAINER) || (battleType & BATTLE_TYPE_TAG)) {
         if (resultMask == BATTLE_RESULT_WIN) {
-            JournalEntry_CreateAndSaveEventTrainer(fieldSystem->journalEntry, fieldSystem->location->mapId, dto->trainerIDs[BATTLER_ENEMY_1], HEAP_ID_FIELD2);
+            JournalEntry_CreateAndSaveEventTrainer(fieldSystem->journalEntry, fieldSystem->location->mapHeaderID, dto->trainerIDs[BATTLER_ENEMY_1], HEAP_ID_FIELD2);
         }
     }
 }
diff --git a/src/field_battle_data_transfer.c b/src/field_battle_data_transfer.c
index c721ad14b8..16dc3f962e 100644
--- a/src/field_battle_data_transfer.c
+++ b/src/field_battle_data_transfer.c
@@ -175,7 +175,7 @@ FieldBattleDTO *FieldBattleDTO_NewCatchingTutorial(enum HeapID heapID, const Fie
     dto->subscreenCursorOn = NULL;
     dto->records = SaveData_GetGameRecords(fieldSystem->saveData);
     dto->journalEntry = fieldSystem->journalEntry;
-    dto->mapHeaderID = fieldSystem->location->mapId;
+    dto->mapHeaderID = fieldSystem->location->mapHeaderID;
 
     FieldBattleDTO_CopyPlayerInfoToTrainerData(dto);
 
@@ -278,7 +278,7 @@ void FieldBattleDTO_InitFromGameState(FieldBattleDTO *dto, const FieldSystem *fi
 
 void FieldBattleDTO_Init(FieldBattleDTO *dto, const FieldSystem *fieldSystem)
 {
-    FieldBattleDTO_InitFromGameState(dto, fieldSystem, fieldSystem->saveData, fieldSystem->location->mapId, fieldSystem->journalEntry, fieldSystem->bagCursor, fieldSystem->battleSubscreenCursorOn);
+    FieldBattleDTO_InitFromGameState(dto, fieldSystem, fieldSystem->saveData, fieldSystem->location->mapHeaderID, fieldSystem->journalEntry, fieldSystem->bagCursor, fieldSystem->battleSubscreenCursorOn);
     FieldBattleDTO_CopyPlayerInfoToTrainerData(dto);
 }
 
@@ -327,7 +327,7 @@ void FieldBattleDTO_InitWithNormalizedMonLevels(FieldBattleDTO *dto, const Field
     dto->records = SaveData_GetGameRecords(fieldSystem->saveData);
     dto->journalEntry = fieldSystem->journalEntry;
     dto->palPad = SaveData_GetPalPad(fieldSystem->saveData);
-    dto->mapHeaderID = fieldSystem->location->mapId;
+    dto->mapHeaderID = fieldSystem->location->mapHeaderID;
     dto->saveData = fieldSystem->saveData;
 
     FieldBattleDTO_CopyPlayerInfoToTrainerData(dto);
@@ -391,7 +391,7 @@ void FieldBattleDTO_InitWithPartyOrder(FieldBattleDTO *dto, const FieldSystem *f
     dto->wiFiHistory = SaveData_WiFiHistory(fieldSystem->saveData);
     dto->records = SaveData_GetGameRecords(fieldSystem->saveData);
     dto->journalEntry = fieldSystem->journalEntry;
-    dto->mapHeaderID = fieldSystem->location->mapId;
+    dto->mapHeaderID = fieldSystem->location->mapHeaderID;
     dto->palPad = SaveData_GetPalPad(fieldSystem->saveData);
     dto->saveData = fieldSystem->saveData;
 
@@ -496,7 +496,7 @@ static int CalcTerrain(const FieldSystem *fieldSystem, enum BattleBackground bac
 static void SetBackgroundAndTerrain(FieldBattleDTO *dto, const FieldSystem *fieldSystem)
 {
     PlayerData *player = FieldOverworldState_GetPlayerData(SaveData_GetFieldOverworldState(fieldSystem->saveData));
-    dto->background = MapHeader_GetBattleBG(fieldSystem->location->mapId);
+    dto->background = MapHeader_GetBattleBG(fieldSystem->location->mapHeaderID);
     if (player->playerState == PLAYER_AVATAR_SURFING) {
         dto->background = BACKGROUND_WATER;
     }
diff --git a/src/field_bgm.c b/src/field_bgm.c
index 6c5b6a37e7..4d55e0f6f3 100644
--- a/src/field_bgm.c
+++ b/src/field_bgm.c
@@ -3,6 +3,7 @@
 #include <nitro.h>
 #include <string.h>
 
+#include "generated/map_headers.h"
 #include "generated/trainer_classes.h"
 
 #include "field/field_system.h"
@@ -104,7 +105,7 @@ const static u16 sTrainerEncounterBGMs[][2] = {
 };
 // clang-format on
 
-static u16 FieldBGM_GetAltMusicForCyclingRoad(FieldSystem *fieldSystem, int headerID);
+static u16 FieldBGM_GetAltMusicForCyclingRoad(FieldSystem *fieldSystem, enum MapHeaderID mapHeaderID);
 static void FieldBGM_GetFadeOutAndWaitFrames(FieldSystem *fieldSystem, int mode, int *fadeOutFrames, int *waitFrames);
 
 void FieldBGM_Stop()
@@ -134,13 +135,13 @@ void FieldBGM_ClearOverride(FieldSystem *fieldSystem)
     *bgm = SEQ_NONE;
 }
 
-u16 FieldBGM_GetEffective(FieldSystem *fieldSystem, enum MapHeaderID mapID)
+u16 FieldBGM_GetEffective(FieldSystem *fieldSystem, enum MapHeaderID mapHeaderID)
 {
     PlayerAvatar *playerAvatar = fieldSystem->playerAvatar;
     int playerState = PlayerAvatar_GetPlayerState(playerAvatar);
 
     if (playerState == PLAYER_AVATAR_SURFING) {
-        switch (mapID) {
+        switch (mapHeaderID) {
         case MAP_HEADER_DISTORTION_WORLD_1F:
         case MAP_HEADER_DISTORTION_WORLD_B1F:
         case MAP_HEADER_DISTORTION_WORLD_B2F:
@@ -161,7 +162,7 @@ u16 FieldBGM_GetEffective(FieldSystem *fieldSystem, enum MapHeaderID mapID)
         return SEQ_POKERADAR;
     }
 
-    u16 bgmID = FieldBGM_GetForMapHeader(fieldSystem, mapID);
+    u16 bgmID = FieldBGM_GetForMapHeader(fieldSystem, mapHeaderID);
 
     if (FieldBGM_GetOverride(fieldSystem) != SEQ_NONE) {
         bgmID = FieldBGM_GetOverride(fieldSystem);
@@ -170,23 +171,23 @@ u16 FieldBGM_GetEffective(FieldSystem *fieldSystem, enum MapHeaderID mapID)
     return bgmID;
 }
 
-u16 FieldBGM_GetForMapHeader(FieldSystem *fieldSystem, int mapID)
+u16 FieldBGM_GetForMapHeader(FieldSystem *fieldSystem, enum MapHeaderID mapHeaderID)
 {
     u16 sdatID;
 
     if (IsNight() == FALSE) {
-        sdatID = MapHeader_GetDayMusicID(mapID);
+        sdatID = MapHeader_GetDayMusicID(mapHeaderID);
     } else {
-        sdatID = MapHeader_GetNightMusicID(mapID);
+        sdatID = MapHeader_GetNightMusicID(mapHeaderID);
     }
 
-    u16 altSdatID = SystemFlag_GetAltMusicForHeader(SaveData_GetVarsFlags(fieldSystem->saveData), mapID);
+    u16 altSdatID = SystemFlag_GetAltMusicForHeader(SaveData_GetVarsFlags(fieldSystem->saveData), mapHeaderID);
 
     if (altSdatID != SEQ_NONE) {
         sdatID = altSdatID;
     }
 
-    altSdatID = FieldBGM_GetAltMusicForCyclingRoad(fieldSystem, mapID);
+    altSdatID = FieldBGM_GetAltMusicForCyclingRoad(fieldSystem, mapHeaderID);
 
     if (altSdatID != SEQ_NONE) {
         sdatID = altSdatID;
@@ -195,20 +196,19 @@ u16 FieldBGM_GetForMapHeader(FieldSystem *fieldSystem, int mapID)
     return sdatID;
 }
 
-static u16 FieldBGM_GetAltMusicForCyclingRoad(FieldSystem *fieldSystem, int headerID)
+static u16 FieldBGM_GetAltMusicForCyclingRoad(FieldSystem *fieldSystem, enum MapHeaderID mapHeaderID)
 {
-    int x, y;
     FieldOverworldState *fieldState = SaveData_GetFieldOverworldState(fieldSystem->saveData);
     Location *location = FieldOverworldState_GetPrevLocation(fieldState);
 
-    x = PlayerAvatar_GetXPos(fieldSystem->playerAvatar);
-    y = PlayerAvatar_GetZPos(fieldSystem->playerAvatar);
+    int x = PlayerAvatar_GetXPos(fieldSystem->playerAvatar);
+    int y = PlayerAvatar_GetZPos(fieldSystem->playerAvatar);
 
-    if (headerID != MAP_HEADER_ROUTE_206) {
+    if (mapHeaderID != MAP_HEADER_ROUTE_206) {
         return SEQ_NONE;
     }
 
-    if ((location->mapId == MAP_HEADER_ROUTE_206_CYCLING_ROAD_NORTH_GATE) || (location->mapId == MAP_HEADER_ROUTE_206_CYCLING_ROAD_SOUTH_GATE)) {
+    if ((location->mapHeaderID == MAP_HEADER_ROUTE_206_CYCLING_ROAD_NORTH_GATE) || (location->mapHeaderID == MAP_HEADER_ROUTE_206_CYCLING_ROAD_SOUTH_GATE)) {
         if (x < 299) {
             return 0;
         }
@@ -291,37 +291,35 @@ u16 FieldBGM_GetEyesMeetForTrainer(enum TrainerID trainerID)
     return bgmID;
 }
 
-void FieldBGM_TryFadeIn(FieldSystem *fieldSystem, int mapID)
+void FieldBGM_TryFadeIn(FieldSystem *fieldSystem, enum MapHeaderID mapHeaderID)
 {
     if (Sound_IsBGMFixed() == 1) {
         return;
     }
 
-    if (Sound_GetCurrentBGM() != FieldBGM_GetForMapHeader(fieldSystem, mapID)) {
+    if (Sound_GetCurrentBGM() != FieldBGM_GetForMapHeader(fieldSystem, mapHeaderID)) {
         Sound_FadeOutBGM(0, 40);
     }
 }
 
-void FieldBGM_PlayForMapHeader(FieldSystem *fieldSystem, int mapID)
+void FieldBGM_PlayForMapHeader(FieldSystem *fieldSystem, enum MapHeaderID mapHeaderID)
 {
-    u16 bgmID;
-
     if (Sound_IsBGMFixed() == 1) {
         return;
     }
 
     Sound_SetScene(SOUND_SCENE_NONE);
 
-    bgmID = FieldBGM_GetForMapHeader(fieldSystem, mapID);
+    u16 bgmID = FieldBGM_GetForMapHeader(fieldSystem, mapHeaderID);
 
     Sound_SetFieldBGM(bgmID);
     Sound_SetSceneAndPlayBGM(SOUND_SCENE_FIELD, bgmID, 1);
 }
 
-void FieldBGM_PlayEffectiveForMapHeader(FieldSystem *fieldSystem, int mapID)
+void FieldBGM_PlayEffectiveForMapHeader(FieldSystem *fieldSystem, enum MapHeaderID mapHeaderID)
 {
-    u16 bgmID = FieldBGM_GetEffective(fieldSystem, mapID);
+    u16 bgmID = FieldBGM_GetEffective(fieldSystem, mapHeaderID);
 
-    Sound_SetFieldBGM(FieldBGM_GetForMapHeader(fieldSystem, mapID));
+    Sound_SetFieldBGM(FieldBGM_GetForMapHeader(fieldSystem, mapHeaderID));
     Sound_SetSceneAndPlayBGM(SOUND_SCENE_FIELD, bgmID, 1);
 }
diff --git a/src/field_map_change.c b/src/field_map_change.c
index 600362ba45..88eea51ba4 100644
--- a/src/field_map_change.c
+++ b/src/field_map_change.c
@@ -26,6 +26,7 @@
 #include "brightness_controller.h"
 #include "communication_system.h"
 #include "field_bgm.h"
+#include "field_map_change_flags.h"
 #include "field_message.h"
 #include "field_overworld_state.h"
 #include "field_overworld_weather.h"
@@ -69,7 +70,6 @@
 #include "unk_020559DC.h"
 #include "unk_0205B33C.h"
 #include "unk_0205C22C.h"
-#include "unk_02070428.h"
 #include "vars_flags.h"
 
 #include "res/text/bank/pokemon_center_2f_common.h"
@@ -188,7 +188,7 @@ static void sub_020530C8(FieldSystem *fieldSystem)
 {
     BOOL inBattleTower;
 
-    switch (fieldSystem->location->mapId) {
+    switch (fieldSystem->location->mapHeaderID) {
     case MAP_HEADER_BATTLE_TOWER:
     case MAP_HEADER_BATTLE_TOWER_ELEVATOR:
     case MAP_HEADER_BATTLE_TOWER_CORRIDOR:
@@ -221,7 +221,7 @@ static void FieldMapChange_SetNewLocation(FieldSystem *fieldSystem, const Locati
         *(fieldSystem->location) = *nextLocation;
     }
 
-    MapHeaderData_Load(fieldSystem, fieldSystem->location->mapId);
+    MapHeaderData_Load(fieldSystem, fieldSystem->location->mapHeaderID);
 
     if (fieldSystem->location->warpId != WARP_ID_NONE) {
         const WarpEvent *warpEvent = MapHeaderData_GetWarpEventByIndex(fieldSystem, fieldSystem->location->warpId);
@@ -247,7 +247,7 @@ void FieldMapChange_Set3DDisplay(FieldSystem *fieldSystem)
 
 void FieldMapChange_UpdateGameData(FieldSystem *fieldSystem, BOOL noWarp)
 {
-    int mapId = fieldSystem->location->mapId;
+    enum MapHeaderID mapHeaderID = fieldSystem->location->mapHeaderID;
     FieldOverworldState *fieldState = SaveData_GetFieldOverworldState(fieldSystem->saveData);
 
     FieldBGM_ClearOverride(fieldSystem);
@@ -270,7 +270,7 @@ void FieldMapChange_UpdateGameData(FieldSystem *fieldSystem, BOOL noWarp)
     }
 
     VarsFlags *varsFlags = SaveData_GetVarsFlags(fieldSystem->saveData);
-    u16 weather = FieldSystem_GetWeather(fieldSystem, mapId);
+    u16 weather = FieldSystem_GetWeather(fieldSystem, mapHeaderID);
 
     if ((weather == OVERWORLD_WEATHER_FOG && SystemFlag_CheckDefogActive(varsFlags) == TRUE)
         || (weather == OVERWORLD_WEATHER_DARK_FLASH && SystemFlag_CheckFlashActive(varsFlags) == TRUE)) {
@@ -281,15 +281,15 @@ void FieldMapChange_UpdateGameData(FieldSystem *fieldSystem, BOOL noWarp)
 
     if (noWarp) {
         int cam1 = FieldOverworldState_GetCameraType(fieldState);
-        int cam2 = MapHeader_GetCameraType(mapId);
+        int cam2 = MapHeader_GetCameraType(mapHeaderID);
 
         GF_ASSERT(cam1 == cam2);
     } else {
-        FieldOverworldState_SetCameraType(fieldState, MapHeader_GetCameraType(mapId));
+        FieldOverworldState_SetCameraType(fieldState, MapHeader_GetCameraType(mapHeaderID));
     }
 
     if (!noWarp) {
-        u16 warpId = GetMapBlackOutWarpId(mapId);
+        u16 warpId = GetMapBlackOutWarpId(mapHeaderID);
 
         if (warpId != 0) {
             FieldOverworldState_SetBlackOutWarpId(fieldState, warpId);
@@ -304,7 +304,7 @@ void FieldMapChange_UpdateGameData(FieldSystem *fieldSystem, BOOL noWarp)
 
 void FieldMapChange_UpdateGameDataDistortionWorld(FieldSystem *fieldSystem, BOOL param1)
 {
-    int mapId = fieldSystem->location->mapId;
+    enum MapHeaderID mapHeaderID = fieldSystem->location->mapHeaderID;
     FieldOverworldState *fieldState = SaveData_GetFieldOverworldState(fieldSystem->saveData);
 
     FieldBGM_ClearOverride(fieldSystem);
@@ -327,7 +327,7 @@ void FieldMapChange_UpdateGameDataDistortionWorld(FieldSystem *fieldSystem, BOOL
     }
 
     if (!param1) {
-        u16 warpId = GetMapBlackOutWarpId(mapId);
+        u16 warpId = GetMapBlackOutWarpId(mapHeaderID);
 
         if (warpId != 0) {
             FieldOverworldState_SetBlackOutWarpId(fieldState, warpId);
@@ -377,7 +377,7 @@ static void FieldMapChange_InitTerrainCollisionManager(FieldSystem *fieldSystem)
 {
     sub_020530C8(fieldSystem);
     GF_ASSERT(fieldSystem->terrainCollisionMan == NULL);
-    MapMatrix_Load(fieldSystem->location->mapId, fieldSystem->mapMatrix);
+    MapMatrix_Load(fieldSystem->location->mapHeaderID, fieldSystem->mapMatrix);
 
     if (SystemVars_CheckHiddenLocation(SaveData_GetVarsFlags(fieldSystem->saveData), HIDDEN_LOCATION_SEABREAK_PATH)) {
         MapMatrix_RevealSeabreakPath(fieldSystem->mapMatrix); // reveal Seabreak Path if Oak's Letter has been used
@@ -417,7 +417,7 @@ static void FieldMapChange_RemoveTerrainCollisionManager(FieldSystem *fieldSyste
 void sub_02053494(FieldSystem *fieldSystem)
 {
     if (fieldSystem->journalEntry != NULL) {
-        void *v0 = JournalEntry_CreateTitle(fieldSystem->location->mapId, 11);
+        void *v0 = JournalEntry_CreateTitle(fieldSystem->location->mapHeaderID, 11);
         JournalEntry_SaveData(fieldSystem->journalEntry, v0, JOURNAL_TITLE);
     }
 }
@@ -427,19 +427,19 @@ static void sub_020534BC(FieldSystem *fieldSystem)
     if (fieldSystem->journalEntry != NULL) {
         FieldOverworldState *owState = SaveData_GetFieldOverworldState(fieldSystem->saveData);
         Location *location = FieldOverworldState_GetSpecialLocation(owState);
-        void *v2 = JournalEntry_CreateTitle(location->mapId, 11);
+        void *v2 = JournalEntry_CreateTitle(location->mapHeaderID, 11);
         JournalEntry_SaveData(fieldSystem->journalEntry, v2, JOURNAL_TITLE);
     }
 }
 
 static void Location_SetToPlayerLocation(Location *location, const FieldSystem *fieldSystem)
 {
-    Location_Set(location, fieldSystem->location->mapId, WARP_ID_NONE, PlayerAvatar_GetXPos(fieldSystem->playerAvatar), PlayerAvatar_GetZPos(fieldSystem->playerAvatar), DIR_SOUTH);
+    Location_Set(location, fieldSystem->location->mapHeaderID, WARP_ID_NONE, PlayerAvatar_GetXPos(fieldSystem->playerAvatar), PlayerAvatar_GetZPos(fieldSystem->playerAvatar), DIR_SOUTH);
 }
 
 static BOOL FieldSystem_IsSaveInUnionRoom(const FieldSystem *fieldSystem)
 {
-    return MapHeader_IsPokemonCenter2F(fieldSystem->location->mapId)
+    return MapHeader_IsPokemonCenter2F(fieldSystem->location->mapHeaderID)
         && fieldSystem->location->x == 7
         && fieldSystem->location->z == 6;
 }
@@ -449,7 +449,7 @@ static void FieldSystem_SetLocationToUnionRoomExit(FieldSystem *fieldSystem)
     Location *exit = FieldOverworldState_GetSpecialLocation(SaveData_GetFieldOverworldState(fieldSystem->saveData));
     VarsFlags *varsFlags = SaveData_GetVarsFlags(fieldSystem->saveData);
 
-    Location_Set(exit, fieldSystem->location->mapId, -1, 8, 2, 1);
+    Location_Set(exit, fieldSystem->location->mapHeaderID, -1, 8, 2, 1);
 }
 
 static BOOL FieldTask_LoadNewGameSpawn(FieldTask *task)
@@ -526,7 +526,7 @@ static BOOL FieldTask_LoadSavedGameMap(FieldTask *task)
         }
 
         sub_02053494(fieldSystem);
-        sub_020705CC(fieldSystem);
+        FieldSystem_RandomizeRoamingPokemonLocations(fieldSystem);
         *state = 2;
         break;
     case 2:
@@ -600,9 +600,7 @@ static BOOL FieldTask_LoadMapFromError(FieldTask *task)
 
 void FieldSystem_StartLoadMapFromErrorTask(FieldSystem *fieldSystem)
 {
-    MapChangeFromErrorData *errorData;
-
-    if (!MapHeader_IsUnionRoom(fieldSystem->location->mapId)) {
+    if (!MapHeader_IsUnionRoom(fieldSystem->location->mapHeaderID)) {
         if (FieldSystem_IsSaveInUnionRoom(fieldSystem)) {
             VarsFlags *varsFlags = SaveData_GetVarsFlags(fieldSystem->saveData);
 
@@ -614,10 +612,10 @@ void FieldSystem_StartLoadMapFromErrorTask(FieldSystem *fieldSystem)
         }
     }
 
-    errorData = Heap_AllocAtEnd(HEAP_ID_FIELD2, sizeof(MapChangeFromErrorData));
+    MapChangeFromErrorData *errorData = Heap_AllocAtEnd(HEAP_ID_FIELD2, sizeof(MapChangeFromErrorData));
     errorData->finishedFlag = FALSE;
 
-    Location_Set(&errorData->location, 466, -1, 8, 14, 0);
+    Location_Set(&errorData->location, MAP_HEADER_UNION_ROOM, -1, 8, 14, 0);
     fieldSystem->mapLoadType = MAP_LOAD_TYPE_UNION;
     FieldSystem_CreateTask(fieldSystem, FieldTask_LoadMapFromError, errorData);
 }
@@ -631,7 +629,7 @@ static BOOL FieldTask_ChangeMap(FieldTask *task)
     switch (mapChangeData->state) {
     case 0:
         Sound_PlayEffect(SEQ_SE_DP_KAIDAN2);
-        FieldBGM_TryFadeIn(fieldSystem, location->mapId);
+        FieldBGM_TryFadeIn(fieldSystem, location->mapHeaderID);
         FieldTransition_FadeOutAndFinishMap(task);
         mapChangeData->state++;
         break;
@@ -644,7 +642,7 @@ static BOOL FieldTask_ChangeMap(FieldTask *task)
             break;
         }
 
-        FieldBGM_PlayForMapHeader(fieldSystem, location->mapId);
+        FieldBGM_PlayForMapHeader(fieldSystem, location->mapHeaderID);
         FieldTransition_StartMapAndFadeIn(task);
         mapChangeData->state++;
         break;
@@ -709,11 +707,11 @@ void FieldTask_ChangeMapByLocation(FieldTask *task, const Location *nextLocation
     FieldTask_InitCall(task, FieldTask_ChangeMapSub, mapChangeSub);
 }
 
-void FieldTask_ChangeMapToLocation(FieldTask *task, int mapId, int warpId, int x, int z, int dir)
+void FieldTask_ChangeMapToLocation(FieldTask *task, enum MapHeaderID mapHeaderID, int warpId, int x, int z, int dir)
 {
     Location location;
 
-    Location_Set(&location, mapId, warpId, x, z, dir);
+    Location_Set(&location, mapHeaderID, warpId, x, z, dir);
     FieldTask_ChangeMapByLocation(task, &location);
 }
 
@@ -725,7 +723,7 @@ static BOOL FieldTask_ChangeMapFull(FieldTask *task)
 
     switch (mapChangeSub->state) {
     case 0:
-        FieldBGM_TryFadeIn(fieldSystem, nextLocation->mapId);
+        FieldBGM_TryFadeIn(fieldSystem, nextLocation->mapHeaderID);
         FieldTransition_FinishMap(task);
         mapChangeSub->state++;
         break;
@@ -738,7 +736,7 @@ static BOOL FieldTask_ChangeMapFull(FieldTask *task)
             break;
         }
 
-        FieldBGM_PlayForMapHeader(fieldSystem, nextLocation->mapId);
+        FieldBGM_PlayForMapHeader(fieldSystem, nextLocation->mapHeaderID);
         FieldTransition_StartMap(task);
         mapChangeSub->state++;
         break;
@@ -750,21 +748,21 @@ static BOOL FieldTask_ChangeMapFull(FieldTask *task)
     return FALSE;
 }
 
-void FieldTask_StartMapChangeFull(FieldTask *task, int mapId, int warpId, int x, int z, int dir)
+void FieldTask_StartMapChangeFull(FieldTask *task, enum MapHeaderID mapHeaderID, int warpId, int x, int z, int dir)
 {
     MapChangeSubData *mapChangeSub = Heap_AllocAtEnd(HEAP_ID_FIELD2, sizeof(MapChangeSubData));
 
     mapChangeSub->state = 0;
 
-    Location_Set(&mapChangeSub->nextLocation, mapId, warpId, x, z, dir);
+    Location_Set(&mapChangeSub->nextLocation, mapHeaderID, warpId, x, z, dir);
     FieldTask_InitCall(task, FieldTask_ChangeMapFull, mapChangeSub);
 }
 
-void FieldTask_StartMapChangeFly(FieldSystem *fieldSystem, int mapId, int warpId, int x, int z, int dir)
+void FieldTask_StartMapChangeFly(FieldSystem *fieldSystem, enum MapHeaderID mapHeaderID, int warpId, int x, int z, int dir)
 {
     Location location;
 
-    Location_Set(&location, mapId, warpId, x, z, dir);
+    Location_Set(&location, mapHeaderID, warpId, x, z, dir);
 
     MapChangeFlyData *mapChangeData = Heap_AllocAtEnd(HEAP_ID_FIELD2, sizeof(MapChangeFlyData));
 
@@ -775,11 +773,11 @@ void FieldTask_StartMapChangeFly(FieldSystem *fieldSystem, int mapId, int warpId
     FieldSystem_CreateTask(fieldSystem, FieldTask_MapChangeFly, mapChangeData);
 }
 
-void FieldTask_ChangeMapChangeFly(FieldTask *task, int mapId, int warpId, int x, int z, int dir)
+void FieldTask_ChangeMapChangeFly(FieldTask *task, enum MapHeaderID mapHeaderID, int warpId, int x, int z, int dir)
 {
     Location location;
 
-    Location_Set(&location, mapId, warpId, x, z, dir);
+    Location_Set(&location, mapHeaderID, warpId, x, z, dir);
 
     MapChangeFlyData *mapChangeData = Heap_AllocAtEnd(HEAP_ID_FIELD2, sizeof(MapChangeFlyData));
 
@@ -798,7 +796,7 @@ static BOOL FieldTask_MapChangeFly(FieldTask *task)
 
     switch (mapChangeData->state) {
     case 0:
-        FieldBGM_TryFadeIn(fieldSystem, location->mapId);
+        FieldBGM_TryFadeIn(fieldSystem, location->mapHeaderID);
         FieldTask_FinishFly(task);
         mapChangeData->state++;
         break;
@@ -812,7 +810,7 @@ static BOOL FieldTask_MapChangeFly(FieldTask *task)
             break;
         }
 
-        FieldBGM_PlayForMapHeader(fieldSystem, location->mapId);
+        FieldBGM_PlayForMapHeader(fieldSystem, location->mapHeaderID);
         FieldSystem_SetFlyFlags(fieldSystem);
         FieldTransition_StartMapAndFadeInFly(task);
         mapChangeData->state++;
@@ -920,7 +918,7 @@ static BOOL FieldTask_MapChangeByFieldWarp(FieldTask *task)
 
     switch (mapChangeData->state) {
     case 0:
-        FieldBGM_TryFadeIn(fieldSystem, location->mapId);
+        FieldBGM_TryFadeIn(fieldSystem, location->mapHeaderID);
         FieldTask_StartFinishFieldMapFieldWarp(task);
         mapChangeData->state++;
         break;
@@ -934,7 +932,7 @@ static BOOL FieldTask_MapChangeByFieldWarp(FieldTask *task)
             break;
         }
 
-        FieldBGM_PlayForMapHeader(fieldSystem, location->mapId);
+        FieldBGM_PlayForMapHeader(fieldSystem, location->mapHeaderID);
 
         if (mapChangeData->fieldWarpType == FIELD_WARP_TYPE_TELEPORT) {
             FieldSystem_SetTeleportFlags(fieldSystem);
@@ -1032,7 +1030,7 @@ static BOOL FieldTask_MapChangeWarp(FieldTask *task)
         break;
     case 1:
         if (mapChangeWarpData->warpFinished) {
-            FieldBGM_TryFadeIn(fieldSystem, nextLocation->mapId);
+            FieldBGM_TryFadeIn(fieldSystem, nextLocation->mapHeaderID);
             FieldTransition_FinishMap(task);
             mapChangeWarpData->state++;
         }
@@ -1046,7 +1044,7 @@ static BOOL FieldTask_MapChangeWarp(FieldTask *task)
             break;
         }
 
-        FieldBGM_PlayForMapHeader(fieldSystem, nextLocation->mapId);
+        FieldBGM_PlayForMapHeader(fieldSystem, nextLocation->mapHeaderID);
         FieldTransition_StartMap(task);
         mapChangeWarpData->state++;
         break;
@@ -1090,13 +1088,13 @@ MapChangeUndergroundContext *MapChangeUndergroundContext_New(FieldSystem *fieldS
     ctx->transitionState = 0;
 
     if (fieldSystem->mapLoadType == MAP_LOAD_TYPE_UNDERGROUND) {
-        ctx->mapId = location->mapId;
+        ctx->mapHeaderID = location->mapHeaderID;
         ctx->dummy = -1;
         ctx->destX = location->x;
         ctx->destZ = location->z;
     } else {
         Location_SetToPlayerLocation(location, fieldSystem);
-        ctx->mapId = MAP_HEADER_UNDERGROUND;
+        ctx->mapHeaderID = MAP_HEADER_UNDERGROUND;
         ctx->dummy = -1;
 
         int matrixX = location->x / MAP_TILES_COUNT_X - 1;
@@ -1214,7 +1212,7 @@ BOOL FieldTask_MapChangeToUnderground(FieldTask *task)
         fieldSystem->mapLoadType = MAP_LOAD_TYPE_UNDERGROUND;
         Overlay_LoadByID(FS_OVERLAY_ID(underground), OVERLAY_LOAD_ASYNC);
         CommManUnderground_InitUnderground(fieldSystem);
-        FieldTask_ChangeMapToLocation(task, ctx->mapId, WARP_ID_NONE, ctx->destX, ctx->destZ, DIR_SOUTH);
+        FieldTask_ChangeMapToLocation(task, ctx->mapHeaderID, WARP_ID_NONE, ctx->destX, ctx->destZ, DIR_SOUTH);
         ctx->state++;
         break;
     case ENTER_UNDERGROUND_START_MAP:
@@ -1280,7 +1278,7 @@ BOOL FieldTask_MapChangeFromUnderground(FieldTask *task)
     case EXIT_UNDERGROUND_LOAD_OVERWORLD:
         fieldSystem->mapLoadType = MAP_LOAD_TYPE_OVERWORLD;
         Overlay_UnloadByID(FS_OVERLAY_ID(underground));
-        FieldTask_ChangeMapToLocation(task, ctx->mapId, WARP_ID_NONE, ctx->destX, ctx->destZ, DIR_SOUTH);
+        FieldTask_ChangeMapToLocation(task, ctx->mapHeaderID, WARP_ID_NONE, ctx->destX, ctx->destZ, DIR_SOUTH);
         ctx->state++;
         break;
     case EXIT_UNDERGROUND_START_MAP:
@@ -1390,7 +1388,7 @@ static BOOL sub_02054538(FieldTask *task)
 
     switch (*state) {
     case 0:
-        FieldBGM_TryFadeIn(fieldSystem, v3->mapId);
+        FieldBGM_TryFadeIn(fieldSystem, v3->mapHeaderID);
         FieldSystem_StartWarpAnimation(fieldSystem, 1, &mapChangeData->unk_04);
         (*state)++;
         break;
@@ -1409,7 +1407,7 @@ static BOOL sub_02054538(FieldTask *task)
             break;
         }
 
-        FieldBGM_PlayForMapHeader(fieldSystem, v3->mapId);
+        FieldBGM_PlayForMapHeader(fieldSystem, v3->mapHeaderID);
         FieldTransition_StartMap(task);
         (*state)++;
         break;
@@ -1450,7 +1448,7 @@ static BOOL sub_02054648(FieldTask *task)
 
     switch (*state) {
     case 0:
-        FieldBGM_TryFadeIn(fieldSystem, v3->mapId);
+        FieldBGM_TryFadeIn(fieldSystem, v3->mapHeaderID);
         FieldTransition_FadeOut(task);
         (*state)++;
         break;
@@ -1467,7 +1465,7 @@ static BOOL sub_02054648(FieldTask *task)
             break;
         }
 
-        FieldBGM_PlayForMapHeader(fieldSystem, v3->mapId);
+        FieldBGM_PlayForMapHeader(fieldSystem, v3->mapHeaderID);
         FieldTransition_StartMap(task);
         (*state)++;
         break;
@@ -1498,7 +1496,7 @@ void sub_02054708(FieldTask *task)
     MI_CpuClear8(mapChangeData, sizeof(MapChangeUnionData));
     Location_SetToPlayerLocation(location, fieldSystem);
 
-    Location_Set(&mapChangeData->location, 466, -1, 8, 14, 0);
+    Location_Set(&mapChangeData->location, MAP_HEADER_UNION_ROOM, -1, 8, 14, 0);
 
     fieldSystem->unk_7C = FieldSystem_InitCommUnionRoom(fieldSystem);
     fieldSystem->unk_80 = sub_0205C22C(fieldSystem->unk_7C);
@@ -1516,7 +1514,7 @@ static BOOL FieldTask_ChangeMapColosseum(FieldTask *task)
     switch (mapChangeData->state) {
     case 0:
         Sound_PlayEffect(SEQ_SE_DP_KAIDAN2);
-        FieldBGM_TryFadeIn(fieldSystem, location->mapId);
+        FieldBGM_TryFadeIn(fieldSystem, location->mapHeaderID);
         FieldTransition_FadeOutAndFinishMap(task);
         mapChangeData->state++;
         break;
@@ -1529,7 +1527,7 @@ static BOOL FieldTask_ChangeMapColosseum(FieldTask *task)
             break;
         }
 
-        FieldBGM_PlayForMapHeader(fieldSystem, location->mapId);
+        FieldBGM_PlayForMapHeader(fieldSystem, location->mapHeaderID);
         FieldTransition_StartMap(task);
         mapChangeData->state++;
         break;
@@ -1541,7 +1539,7 @@ static BOOL FieldTask_ChangeMapColosseum(FieldTask *task)
     return FALSE;
 }
 
-void FieldTask_StartChangeMapColosseum(FieldTask *task, int mapId, int warpId, int x, int z, int dir)
+void FieldTask_StartChangeMapColosseum(FieldTask *task, enum MapHeaderID mapHeaderID, int warpId, int x, int z, int dir)
 {
     Location nextLocation;
     FieldSystem *fieldSystem = FieldTask_GetFieldSystem(task);
@@ -1553,7 +1551,7 @@ void FieldTask_StartChangeMapColosseum(FieldTask *task, int mapId, int warpId, i
 
     MapChangeData *mapChangeData = Heap_AllocAtEnd(HEAP_ID_FIELD2, sizeof(MapChangeData));
 
-    Location_Set(&nextLocation, mapId, warpId, x, z, dir);
+    Location_Set(&nextLocation, mapHeaderID, warpId, x, z, dir);
 
     mapChangeData->state = 0;
     mapChangeData->nextLocation = nextLocation;
diff --git a/src/unk_02070428.c b/src/field_map_change_flags.c
similarity index 58%
rename from src/unk_02070428.c
rename to src/field_map_change_flags.c
index e6286520f8..fc5977c8d6 100644
--- a/src/unk_02070428.c
+++ b/src/field_map_change_flags.c
@@ -1,8 +1,10 @@
-#include "unk_02070428.h"
+#include "field_map_change_flags.h"
 
 #include <nitro.h>
 #include <string.h>
 
+#include "generated/map_headers.h"
+
 #include "struct_defs/player_data.h"
 #include "struct_defs/special_encounter.h"
 
@@ -23,43 +25,41 @@
 #include "system_vars.h"
 #include "vars_flags.h"
 
-static BOOL sub_020705DC(FieldSystem *fieldSystem);
-static BOOL sub_02070610(FieldSystem *fieldSystem);
+static BOOL CreateFlyLocationJournalEvent(FieldSystem *fieldSystem);
+static BOOL CreateMapTransitionJournalEvent(FieldSystem *fieldSystem);
 
-void sub_02070428(FieldSystem *fieldSystem, BOOL param1)
+void FieldSystem_SetTemporaryMapChange(FieldSystem *fieldSystem, BOOL temporaryMapChange)
 {
-    fieldSystem->unk_B8 = param1;
+    fieldSystem->temporaryMapChange = temporaryMapChange;
 }
 
 void FieldSystem_InitFlagsOnMapChange(FieldSystem *fieldSystem)
 {
-    sub_020705DC(fieldSystem);
+    CreateFlyLocationJournalEvent(fieldSystem);
     SystemFlag_HandleForceBikingInGate(SaveData_GetVarsFlags(fieldSystem->saveData), HANDLE_FLAG_CLEAR);
 
     SystemFlag_HandleStrengthActive(SaveData_GetVarsFlags(fieldSystem->saveData), HANDLE_FLAG_CLEAR);
 
-    TryUnlockFlyLocationByMap(fieldSystem, fieldSystem->location->mapId);
+    TryUnlockFlyLocationByMap(fieldSystem, fieldSystem->location->mapHeaderID);
     SpecialEncounter_SetFluteFactor(SaveData_GetSpecialEncounters(fieldSystem->saveData), FLUTE_FACTOR_NONE);
 
     fieldSystem->wildBattleMetadata.encounterAttempts = 0;
 
     if (SystemFlag_CheckSafariGameActive(SaveData_GetVarsFlags(fieldSystem->saveData)) == FALSE) {
-        SpecialEncounter *v0;
-
-        v0 = SaveData_GetSpecialEncounters(fieldSystem->saveData);
-        RoamingPokemon_UpdatePlayerRecentRoutes(v0, fieldSystem->location->mapId);
-        RoamingPokemon_MoveAllLocations(v0);
+        SpecialEncounter *speEnc = SaveData_GetSpecialEncounters(fieldSystem->saveData);
+        RoamingPokemon_UpdatePlayerRecentRoutes(speEnc, fieldSystem->location->mapHeaderID);
+        RoamingPokemon_MoveAllLocations(speEnc);
     }
 }
 
 void FieldSystem_InitFlagsWarp(FieldSystem *fieldSystem)
 {
-    if (fieldSystem->unk_B8 == 1) {
+    if (fieldSystem->temporaryMapChange == TRUE) {
         return;
     }
 
-    if (sub_020705DC(fieldSystem) == 0) {
-        sub_02070610(fieldSystem);
+    if (CreateFlyLocationJournalEvent(fieldSystem) == FALSE) {
+        CreateMapTransitionJournalEvent(fieldSystem);
     }
 
     SystemFlag_HandleForceBikingInGate(SaveData_GetVarsFlags(fieldSystem->saveData), HANDLE_FLAG_CLEAR);
@@ -67,36 +67,34 @@ void FieldSystem_InitFlagsWarp(FieldSystem *fieldSystem)
 
     SystemFlag_HandleStrengthActive(SaveData_GetVarsFlags(fieldSystem->saveData), HANDLE_FLAG_CLEAR);
 
-    TryUnlockFlyLocationByMap(fieldSystem, fieldSystem->location->mapId);
+    TryUnlockFlyLocationByMap(fieldSystem, fieldSystem->location->mapHeaderID);
     SpecialEncounter_SetFluteFactor(SaveData_GetSpecialEncounters(fieldSystem->saveData), FLUTE_FACTOR_NONE);
 
     fieldSystem->wildBattleMetadata.encounterAttempts = 0;
 
     {
-        SpecialEncounter *v0;
-
-        v0 = SaveData_GetSpecialEncounters(fieldSystem->saveData);
-        RoamingPokemon_UpdatePlayerRecentRoutes(v0, fieldSystem->location->mapId);
+        SpecialEncounter *speEnc = SaveData_GetSpecialEncounters(fieldSystem->saveData);
+        RoamingPokemon_UpdatePlayerRecentRoutes(speEnc, fieldSystem->location->mapHeaderID);
     }
 
-    if (!MapHeader_IsCave(fieldSystem->location->mapId)) {
-        VarsFlags *v1 = SaveData_GetVarsFlags(fieldSystem->saveData);
+    if (!MapHeader_IsCave(fieldSystem->location->mapHeaderID)) {
+        VarsFlags *varsFlags = SaveData_GetVarsFlags(fieldSystem->saveData);
 
-        SystemFlag_ClearFlashActive(v1);
-        SystemFlag_ClearDefogActive(v1);
+        SystemFlag_ClearFlashActive(varsFlags);
+        SystemFlag_ClearDefogActive(varsFlags);
     }
 
     {
-        PlayerData *v2 = FieldOverworldState_GetPlayerData(SaveData_GetFieldOverworldState(fieldSystem->saveData));
+        PlayerData *playerData = FieldOverworldState_GetPlayerData(SaveData_GetFieldOverworldState(fieldSystem->saveData));
 
-        if ((v2->playerState == PLAYER_AVATAR_CYCLING) && (MapHeader_IsBikeAllowed(fieldSystem->location->mapId) == 0)) {
-            v2->playerState = PLAYER_AVATAR_WALKING;
-        } else if (v2->playerState == PLAYER_AVATAR_SURFING) {
-            v2->playerState = PLAYER_AVATAR_WALKING;
+        if (playerData->playerState == PLAYER_AVATAR_CYCLING && MapHeader_IsBikeAllowed(fieldSystem->location->mapHeaderID) == FALSE) {
+            playerData->playerState = PLAYER_AVATAR_WALKING;
+        } else if (playerData->playerState == PLAYER_AVATAR_SURFING) {
+            playerData->playerState = PLAYER_AVATAR_WALKING;
         }
     }
 
-    if (MapHeader_IsOnMainMatrix(fieldSystem->location->mapId)) {
+    if (MapHeader_IsOnMainMatrix(fieldSystem->location->mapHeaderID)) {
         OverworldMapHistory *mapHistory = FieldOverworldState_GetMapHistory(SaveData_GetFieldOverworldState(fieldSystem->saveData));
         OverworldMapHistory_PushViaWarp(mapHistory, fieldSystem->location->x, fieldSystem->location->z);
     }
@@ -126,29 +124,29 @@ void FieldSystem_ClearPartnerTrainer(FieldSystem *fieldSystem)
     SystemVars_SetPartnerTrainerID(varsFlags, 0);
 }
 
-void sub_020705CC(FieldSystem *fieldSystem)
+void FieldSystem_RandomizeRoamingPokemonLocations(FieldSystem *fieldSystem)
 {
     RoamingPokemon_RandomizeAllLocations(SaveData_GetSpecialEncounters(fieldSystem->saveData));
 }
 
-static BOOL sub_020705DC(FieldSystem *fieldSystem)
+static BOOL CreateFlyLocationJournalEvent(FieldSystem *fieldSystem)
 {
-    int v0 = GetMapFlyWarpId(fieldSystem->location->mapId);
+    int flyLocation = GetMapFlyWarpId(fieldSystem->location->mapHeaderID);
 
-    if (v0 != 0 && CheckFlyLocationUnlocked(fieldSystem, v0) == 0) {
-        JournalEntry_CreateAndSaveEventArrivedInLocation(fieldSystem->journalEntry, fieldSystem->location->mapId, HEAP_ID_FIELD3);
+    if (flyLocation != MAP_HEADER_EVERYWHERE && CheckFlyLocationUnlocked(fieldSystem, flyLocation) == FALSE) {
+        JournalEntry_CreateAndSaveEventArrivedInLocation(fieldSystem->journalEntry, fieldSystem->location->mapHeaderID, HEAP_ID_FIELD3);
         return TRUE;
     }
 
     return FALSE;
 }
 
-static BOOL sub_02070610(FieldSystem *fieldSystem)
+static BOOL CreateMapTransitionJournalEvent(FieldSystem *fieldSystem)
 {
     Location *location = FieldOverworldState_GetPrevLocation(SaveData_GetFieldOverworldState(fieldSystem->saveData));
 
-    if (location->mapId != fieldSystem->location->mapId) {
-        JournalEntry_CreateAndSaveEventMapTransition(SaveData_GetTrainerInfo(fieldSystem->saveData), fieldSystem->journalEntry, fieldSystem->location->mapId, location->mapId, HEAP_ID_FIELD3);
+    if (location->mapHeaderID != fieldSystem->location->mapHeaderID) {
+        JournalEntry_CreateAndSaveEventMapTransition(SaveData_GetTrainerInfo(fieldSystem->saveData), fieldSystem->journalEntry, fieldSystem->location->mapHeaderID, location->mapHeaderID, HEAP_ID_FIELD3);
         return TRUE;
     }
 
diff --git a/src/field_move_tasks.c b/src/field_move_tasks.c
index e414dac72a..4395f689d9 100644
--- a/src/field_move_tasks.c
+++ b/src/field_move_tasks.c
@@ -17,7 +17,9 @@
 #include "overlay005/ov5_021DFB54.h"
 #include "overlay005/ov5_021F101C.h"
 #include "overlay006/field_warp.h"
+#include "overlay006/hm_cut_in.h"
 
+#include "field_map_change.h"
 #include "field_overworld_state.h"
 #include "field_task.h"
 #include "heap.h"
@@ -31,6 +33,7 @@
 #include "player_move.h"
 #include "save_player.h"
 #include "script_manager.h"
+#include "spawn_locations.h"
 #include "start_menu.h"
 #include "system_flags.h"
 #include "terrain_collision_manager.h"
@@ -210,7 +213,7 @@ BOOL FieldMoves_FlyTask(FieldTask *task)
 
         Location location;
         Location_InitFly(destination, &location);
-        FieldTask_ChangeMapChangeFly(task, location.mapId, WARP_ID_NONE, location.x, location.z, DIR_SOUTH);
+        FieldTask_ChangeMapChangeFly(task, location.mapHeaderID, WARP_ID_NONE, location.x, location.z, DIR_SOUTH);
 
         Heap_Free(ctx);
     }
@@ -235,7 +238,7 @@ void FieldMoves_SetUsableMoves(FieldSystem *fieldSystem, FieldMoveContext *field
     int currTileBehavior;
 
     fieldMoveContext->fieldSystem = fieldSystem;
-    fieldMoveContext->mapId = fieldSystem->location->mapId;
+    fieldMoveContext->mapHeaderID = fieldSystem->location->mapHeaderID;
     fieldMoveContext->usableMoves = 0;
 
     if (PlayerAvatar_DistortionGravityChanged(fieldSystem->playerAvatar) == TRUE) {
@@ -371,7 +374,7 @@ static enum FieldMoveError FieldMoves_CheckFly(const FieldMoveContext *fieldMove
         return FIELD_MOVE_ERROR_BADGE;
     }
 
-    if (MapHeader_IsFlyAllowed(fieldMoveContext->mapId) == FALSE) {
+    if (MapHeader_IsFlyAllowed(fieldMoveContext->mapHeaderID) == FALSE) {
         return FIELD_MOVE_ERROR_LOCATION;
     }
 
@@ -707,7 +710,7 @@ static enum FieldMoveError FieldMoves_CheckTeleport(const FieldMoveContext *fiel
         return FIELD_MOVE_ERROR_LOCATION;
     }
 
-    if (MapHeader_IsTeleportAllowed(fieldMoveContext->mapId) == FALSE) {
+    if (MapHeader_IsTeleportAllowed(fieldMoveContext->mapHeaderID) == FALSE) {
         return FIELD_MOVE_ERROR_LOCATION;
     }
 
@@ -754,7 +757,7 @@ static enum FieldMoveError FieldMoves_CheckDig(const FieldMoveContext *fieldMove
         return FIELD_MOVE_ERROR_LOCATION;
     }
 
-    if (!((MapHeader_IsCave(fieldMoveContext->mapId) == TRUE) && (MapHeader_IsEscapeRopeAllowed(fieldMoveContext->mapId) == TRUE))) {
+    if (!((MapHeader_IsCave(fieldMoveContext->mapHeaderID) == TRUE) && (MapHeader_IsEscapeRopeAllowed(fieldMoveContext->mapHeaderID) == TRUE))) {
         return FIELD_MOVE_ERROR_LOCATION;
     }
 
@@ -785,7 +788,7 @@ static BOOL FieldMoves_DigTask(FieldTask *task)
     UnkStruct_020711C8 *v1 = FieldTask_GetEnv(task);
     FieldWarp *fieldWarp = FieldWarp_InitDig(fieldSystem, v1->unk_00, HEAP_ID_FIELD2);
 
-    void *journalEntryLocationEvent = JournalEntry_CreateEventUsedMove(FIELD_MOVE_DIG, fieldSystem->location->mapId, HEAP_ID_FIELD1);
+    void *journalEntryLocationEvent = JournalEntry_CreateEventUsedMove(FIELD_MOVE_DIG, fieldSystem->location->mapHeaderID, HEAP_ID_FIELD1);
     JournalEntry_SaveData(fieldSystem->journalEntry, journalEntryLocationEvent, JOURNAL_LOCATION);
 
     Heap_Free(v1);
@@ -821,7 +824,7 @@ static void FieldMoves_SetSweetScentTask(FieldMovePokemon *fieldMoveMon, const F
     startMenu->taskData = v2;
     startMenu->state = START_MENU_STATE_NEW_TASK;
 
-    v4 = JournalEntry_CreateEventUsedMove(FIELD_MOVE_SWEET_SCENT, fieldSystem->location->mapId, HEAP_ID_FIELD2);
+    v4 = JournalEntry_CreateEventUsedMove(FIELD_MOVE_SWEET_SCENT, fieldSystem->location->mapHeaderID, HEAP_ID_FIELD2);
     JournalEntry_SaveData(fieldSystem->journalEntry, v4, JOURNAL_LOCATION);
 }
 
diff --git a/src/field_system.c b/src/field_system.c
index 6fc0cb2ee1..3e39e2d308 100644
--- a/src/field_system.c
+++ b/src/field_system.c
@@ -244,7 +244,7 @@ static void HandleFieldInput(FieldSystem *fieldSystem)
     }
 
     enum MapLoadType loadType = fieldSystem->mapLoadType;
-    if (fieldSystem->location->mapId == MAP_HEADER_BATTLE_TOWER) {
+    if (fieldSystem->location->mapHeaderID == MAP_HEADER_BATTLE_TOWER) {
         loadType = MAP_LOAD_TYPE_OVERWORLD;
     }
 
diff --git a/src/great_marsh_lookout.c b/src/great_marsh_lookout.c
index 4830f4d9dc..c16c01973c 100644
--- a/src/great_marsh_lookout.c
+++ b/src/great_marsh_lookout.c
@@ -11,6 +11,7 @@
 #include "overlay006/great_marsh_lookout_sprite.h"
 
 #include "field_map_change.h"
+#include "field_map_change_flags.h"
 #include "field_task.h"
 #include "field_transition.h"
 #include "heap.h"
@@ -21,7 +22,6 @@
 #include "system.h"
 #include "system_flags.h"
 #include "unk_02056B30.h"
-#include "unk_02070428.h"
 #include "vars_flags.h"
 
 // Data used for the Great Marsh lookout binoculars scene.
@@ -55,7 +55,7 @@ static BOOL Task_GreatMarshLookout(FieldTask *taskMan)
 
     switch (lookout->state) {
     case 0:
-        sub_02070428(fieldSystem, 1);
+        FieldSystem_SetTemporaryMapChange(fieldSystem, TRUE);
         GreatMarshBinoculars_SetNextLocationWithCoords(lookout->numCycles, lookout->binocularsData);
         lookout->nextLocation = GreatMarshBinoculars_GetLocation(lookout->binocularsData);
         FieldTransition_FadeOut(taskMan);
@@ -124,7 +124,7 @@ static BOOL Task_GreatMarshLookout(FieldTask *taskMan)
         }
         break;
     case 8:
-        sub_02070428(fieldSystem, 0);
+        FieldSystem_SetTemporaryMapChange(fieldSystem, FALSE);
         GreatMarshBinoculars_FreeData(lookout->binocularsData);
         GreatMarshLookout_FreeSpriteManager(lookout->spriteResources);
         Heap_Free(lookout);
diff --git a/src/item_use_functions.c b/src/item_use_functions.c
index 8254f6dc92..3c4bdf4dcd 100644
--- a/src/item_use_functions.c
+++ b/src/item_use_functions.c
@@ -184,7 +184,7 @@ void ItemUseContext_Init(FieldSystem *fieldSystem, ItemUseContext *ctxOut)
     }
 
     ctxOut->fieldSystem = fieldSystem;
-    ctxOut->mapHeaderID = fieldSystem->location->mapId;
+    ctxOut->mapHeaderID = fieldSystem->location->mapHeaderID;
     ctxOut->hasPartner = SystemFlag_CheckHasPartner(SaveData_GetVarsFlags(fieldSystem->saveData));
     ctxOut->playerState = PlayerAvatar_GetPlayerState(fieldSystem->playerAvatar);
 
@@ -221,7 +221,7 @@ void ItemUseContext_Init(FieldSystem *fieldSystem, ItemUseContext *ctxOut)
 static void ItemUseContext_InitForDistortionWorld(FieldSystem *fieldSystem, ItemUseContext *ctxOut)
 {
     ctxOut->fieldSystem = fieldSystem;
-    ctxOut->mapHeaderID = fieldSystem->location->mapId;
+    ctxOut->mapHeaderID = fieldSystem->location->mapHeaderID;
     ctxOut->hasPartner = SystemFlag_CheckHasPartner(SaveData_GetVarsFlags(fieldSystem->saveData));
     ctxOut->playerState = PlayerAvatar_GetPlayerState(fieldSystem->playerAvatar);
     ctxOut->currTileBehavior = PlayerAvatar_GetDistortionCurrTileBehaviour(fieldSystem->playerAvatar);
@@ -437,7 +437,7 @@ static BOOL MountOrUnmountBicycle(FieldTask *task)
             PlayerAvatar_RequestChangeState(fieldSystem->playerAvatar);
 
             FieldBGM_SetOverride(fieldSystem, SEQ_NONE);
-            FieldBGM_TryFadeOut(fieldSystem, FieldBGM_GetEffective(fieldSystem, fieldSystem->location->mapId), 1);
+            FieldBGM_TryFadeOut(fieldSystem, FieldBGM_GetEffective(fieldSystem, fieldSystem->location->mapHeaderID), 1);
         } else {
             FieldBGM_SetOverride(fieldSystem, SEQ_BICYCLE);
             FieldBGM_TryFadeOut(fieldSystem, SEQ_BICYCLE, 1);
diff --git a/src/location.c b/src/location.c
index 79e7ac56ba..84b8881e6e 100644
--- a/src/location.c
+++ b/src/location.c
@@ -6,7 +6,7 @@
 #include "savedata.h"
 
 static const Location sPlayerStartLocation = {
-    .mapId = MAP_HEADER_TWINLEAF_TOWN_PLAYER_HOUSE_2F,
+    .mapHeaderID = MAP_HEADER_TWINLEAF_TOWN_PLAYER_HOUSE_2F,
     .warpId = WARP_ID_NONE,
     .x = 4,
     .z = 6,
@@ -14,7 +14,7 @@ static const Location sPlayerStartLocation = {
 };
 
 static const Location sPlayerFirstRespawnLocation = {
-    .mapId = MAP_HEADER_TWINLEAF_TOWN,
+    .mapHeaderID = MAP_HEADER_TWINLEAF_TOWN,
     .warpId = WARP_ID_NONE,
     .x = 116,
     .z = 886,
diff --git a/src/map_header.c b/src/map_header.c
index 6240f8cfd8..dfc794b19f 100644
--- a/src/map_header.c
+++ b/src/map_header.c
@@ -5,32 +5,32 @@
 
 #include "data/map_headers.h"
 
-u32 MapHeader_IDBoundsCheck(u32 headerID)
+enum MapHeaderID MapHeader_IDBoundsCheck(enum MapHeaderID mapHeaderID)
 {
-    if (headerID >= NELEMS(sMapHeaders)) {
+    if (mapHeaderID >= NELEMS(sMapHeaders)) {
         GF_ASSERT(FALSE);
-        return 3;
+        return MAP_HEADER_JUBILIFE_CITY;
     }
 
-    return headerID;
+    return mapHeaderID;
 }
 
-u16 MapHeader_GetAreaDataArchiveID(u32 headerID)
+u16 MapHeader_GetAreaDataArchiveID(enum MapHeaderID mapHeaderID)
 {
-    headerID = MapHeader_IDBoundsCheck(headerID);
-    return sMapHeaders[headerID].areaDataArchiveID;
+    mapHeaderID = MapHeader_IDBoundsCheck(mapHeaderID);
+    return sMapHeaders[mapHeaderID].areaDataArchiveID;
 }
 
-u16 MapHeader_GetPreloadedMapObjectsArchiveID(u32 headerID)
+u16 MapHeader_GetPreloadedMapObjectsArchiveID(enum MapHeaderID mapHeaderID)
 {
-    headerID = MapHeader_IDBoundsCheck(headerID);
-    return sMapHeaders[headerID].preloadedMapObjectsArchiveID;
+    mapHeaderID = MapHeader_IDBoundsCheck(mapHeaderID);
+    return sMapHeaders[mapHeaderID].preloadedMapObjectsArchiveID;
 }
 
-u16 MapHeader_GetMapMatrixID(u32 headerID)
+u16 MapHeader_GetMapMatrixID(enum MapHeaderID mapHeaderID)
 {
-    headerID = MapHeader_IDBoundsCheck(headerID);
-    u16 mapMatrixID = sMapHeaders[headerID].mapMatrixID;
+    mapHeaderID = MapHeader_IDBoundsCheck(mapHeaderID);
+    u16 mapMatrixID = sMapHeaders[mapHeaderID].mapMatrixID;
 
     if (mapMatrixID == 22 && gGameVersion == VERSION_PEARL) {
         mapMatrixID = 23;
@@ -39,183 +39,183 @@ u16 MapHeader_GetMapMatrixID(u32 headerID)
     return mapMatrixID;
 }
 
-u32 MapHeader_GetMsgArchiveID(u32 headerID)
+u32 MapHeader_GetMsgArchiveID(enum MapHeaderID mapHeaderID)
 {
-    headerID = MapHeader_IDBoundsCheck(headerID);
-    return sMapHeaders[headerID].msgArchiveID;
+    mapHeaderID = MapHeader_IDBoundsCheck(mapHeaderID);
+    return sMapHeaders[mapHeaderID].msgArchiveID;
 }
 
-u32 MapHeader_GetScriptsArchiveID(u32 headerID)
+u32 MapHeader_GetScriptsArchiveID(enum MapHeaderID mapHeaderID)
 {
-    headerID = MapHeader_IDBoundsCheck(headerID);
-    return sMapHeaders[headerID].scriptsArchiveID;
+    mapHeaderID = MapHeader_IDBoundsCheck(mapHeaderID);
+    return sMapHeaders[mapHeaderID].scriptsArchiveID;
 }
 
-u32 MapHeader_GetInitScriptsArchiveID(u32 headerID)
+u32 MapHeader_GetInitScriptsArchiveID(enum MapHeaderID mapHeaderID)
 {
-    headerID = MapHeader_IDBoundsCheck(headerID);
-    return sMapHeaders[headerID].initScriptsArchiveID;
+    mapHeaderID = MapHeader_IDBoundsCheck(mapHeaderID);
+    return sMapHeaders[mapHeaderID].initScriptsArchiveID;
 }
 
-u16 MapHeader_GetDayMusicID(u32 headerID)
+u16 MapHeader_GetDayMusicID(enum MapHeaderID mapHeaderID)
 {
-    headerID = MapHeader_IDBoundsCheck(headerID);
-    return sMapHeaders[headerID].dayMusicID;
+    mapHeaderID = MapHeader_IDBoundsCheck(mapHeaderID);
+    return sMapHeaders[mapHeaderID].dayMusicID;
 }
 
-u16 MapHeader_GetNightMusicID(u32 headerID)
+u16 MapHeader_GetNightMusicID(enum MapHeaderID mapHeaderID)
 {
-    headerID = MapHeader_IDBoundsCheck(headerID);
-    return sMapHeaders[headerID].nightMusicID;
+    mapHeaderID = MapHeader_IDBoundsCheck(mapHeaderID);
+    return sMapHeaders[mapHeaderID].nightMusicID;
 }
 
-BOOL MapHeader_HasWildEncounters(u32 headerID)
+BOOL MapHeader_HasWildEncounters(enum MapHeaderID mapHeaderID)
 {
-    headerID = MapHeader_IDBoundsCheck(headerID);
-    return sMapHeaders[headerID].wildEncountersArchiveID != 65535;
+    mapHeaderID = MapHeader_IDBoundsCheck(mapHeaderID);
+    return sMapHeaders[mapHeaderID].wildEncountersArchiveID != 65535;
 }
 
-u32 MapHeader_GetWildEncountersArchiveID(u32 headerID)
+u32 MapHeader_GetWildEncountersArchiveID(enum MapHeaderID mapHeaderID)
 {
-    headerID = MapHeader_IDBoundsCheck(headerID);
-    return sMapHeaders[headerID].wildEncountersArchiveID;
+    mapHeaderID = MapHeader_IDBoundsCheck(mapHeaderID);
+    return sMapHeaders[mapHeaderID].wildEncountersArchiveID;
 }
 
-u32 MapHeader_GetEventsArchiveID(u32 headerID)
+u32 MapHeader_GetEventsArchiveID(enum MapHeaderID mapHeaderID)
 {
-    headerID = MapHeader_IDBoundsCheck(headerID);
-    return sMapHeaders[headerID].eventsArchiveID;
+    mapHeaderID = MapHeader_IDBoundsCheck(mapHeaderID);
+    return sMapHeaders[mapHeaderID].eventsArchiveID;
 }
 
-u32 MapHeader_GetMapLabelTextID(u32 headerID)
+u32 MapHeader_GetMapLabelTextID(enum MapHeaderID mapHeaderID)
 {
-    headerID = MapHeader_IDBoundsCheck(headerID);
-    return sMapHeaders[headerID].mapLabelTextID;
+    mapHeaderID = MapHeader_IDBoundsCheck(mapHeaderID);
+    return sMapHeaders[mapHeaderID].mapLabelTextID;
 }
 
-u8 MapHeader_GetMapLabelWindowID(u32 headerID)
+u8 MapHeader_GetMapLabelWindowID(enum MapHeaderID mapHeaderID)
 {
-    headerID = MapHeader_IDBoundsCheck(headerID);
-    return sMapHeaders[headerID].mapLabelWindowID;
+    mapHeaderID = MapHeader_IDBoundsCheck(mapHeaderID);
+    return sMapHeaders[mapHeaderID].mapLabelWindowID;
 }
 
-u32 MapHeader_GetWeatherType(u32 headerID)
+u32 MapHeader_GetWeatherType(enum MapHeaderID mapHeaderID)
 {
-    headerID = MapHeader_IDBoundsCheck(headerID);
-    return sMapHeaders[headerID].weather;
+    mapHeaderID = MapHeader_IDBoundsCheck(mapHeaderID);
+    return sMapHeaders[mapHeaderID].weather;
 }
 
-u32 MapHeader_GetCameraType(u32 headerID)
+u32 MapHeader_GetCameraType(enum MapHeaderID mapHeaderID)
 {
-    headerID = MapHeader_IDBoundsCheck(headerID);
-    return sMapHeaders[headerID].cameraType;
+    mapHeaderID = MapHeader_IDBoundsCheck(mapHeaderID);
+    return sMapHeaders[mapHeaderID].cameraType;
 }
 
-enum BattleBackground MapHeader_GetBattleBG(u32 headerID)
+enum BattleBackground MapHeader_GetBattleBG(enum MapHeaderID mapHeaderID)
 {
-    headerID = MapHeader_IDBoundsCheck(headerID);
-    return sMapHeaders[headerID].battleBG;
+    mapHeaderID = MapHeader_IDBoundsCheck(mapHeaderID);
+    return sMapHeaders[mapHeaderID].battleBG;
 }
 
-BOOL MapHeader_IsEscapeRopeAllowed(u32 headerID)
+BOOL MapHeader_IsEscapeRopeAllowed(enum MapHeaderID mapHeaderID)
 {
-    headerID = MapHeader_IDBoundsCheck(headerID);
-    return sMapHeaders[headerID].isEscapeRopeAllowed;
+    mapHeaderID = MapHeader_IDBoundsCheck(mapHeaderID);
+    return sMapHeaders[mapHeaderID].isEscapeRopeAllowed;
 }
 
-BOOL MapHeader_IsFlyAllowed(u32 headerID)
+BOOL MapHeader_IsFlyAllowed(enum MapHeaderID mapHeaderID)
 {
-    headerID = MapHeader_IDBoundsCheck(headerID);
-    return sMapHeaders[headerID].isFlyAllowed;
+    mapHeaderID = MapHeader_IDBoundsCheck(mapHeaderID);
+    return sMapHeaders[mapHeaderID].isFlyAllowed;
 }
 
-BOOL MapHeader_IsBikeAllowed(u32 headerID)
+BOOL MapHeader_IsBikeAllowed(enum MapHeaderID mapHeaderID)
 {
-    headerID = MapHeader_IDBoundsCheck(headerID);
-    return sMapHeaders[headerID].isBikeAllowed;
+    mapHeaderID = MapHeader_IDBoundsCheck(mapHeaderID);
+    return sMapHeaders[mapHeaderID].isBikeAllowed;
 }
 
-u32 MapHeader_GetMapType(u32 headerID)
+u32 MapHeader_GetMapType(enum MapHeaderID mapHeaderID)
 {
-    headerID = MapHeader_IDBoundsCheck(headerID);
-    return sMapHeaders[headerID].mapType;
+    mapHeaderID = MapHeader_IDBoundsCheck(mapHeaderID);
+    return sMapHeaders[mapHeaderID].mapType;
 }
 
-BOOL MapHeader_IsTeleportAllowed(u32 headerID)
+BOOL MapHeader_IsTeleportAllowed(enum MapHeaderID mapHeaderID)
 {
-    if (MapHeader_IsFlyAllowed(headerID) == FALSE) {
+    if (MapHeader_IsFlyAllowed(mapHeaderID) == FALSE) {
         return FALSE;
     }
 
-    return MapHeader_GetMapType(headerID) != MAP_TYPE_TOWN_CITY;
+    return MapHeader_GetMapType(mapHeaderID) != MAP_TYPE_TOWN_CITY;
 }
 
-BOOL MapHeader_IsOnMainMatrix(u32 headerID)
+BOOL MapHeader_IsOnMainMatrix(enum MapHeaderID mapHeaderID)
 {
-    return MapHeader_GetMapMatrixID(headerID) == 0;
+    return MapHeader_GetMapMatrixID(mapHeaderID) == 0;
 }
 
-BOOL MapHeader_IsPokemonCenter(u32 headerID)
+BOOL MapHeader_IsPokemonCenter(enum MapHeaderID mapHeaderID)
 {
-    return MapHeader_GetMapType(headerID) == MAP_TYPE_POKECENTER;
+    return MapHeader_GetMapType(mapHeaderID) == MAP_TYPE_POKECENTER;
 }
 
-BOOL MapHeader_IsCave(u32 headerID)
+BOOL MapHeader_IsCave(enum MapHeaderID mapHeaderID)
 {
-    return MapHeader_GetMapType(headerID) == MAP_TYPE_CAVE;
+    return MapHeader_GetMapType(mapHeaderID) == MAP_TYPE_CAVE;
 }
 
-BOOL MapHeader_IsBuilding(u32 headerID)
+BOOL MapHeader_IsBuilding(enum MapHeaderID mapHeaderID)
 {
-    return MapHeader_GetMapType(headerID) == MAP_TYPE_INDOORS
-        || MapHeader_GetMapType(headerID) == MAP_TYPE_POKECENTER;
+    return MapHeader_GetMapType(mapHeaderID) == MAP_TYPE_INDOORS
+        || MapHeader_GetMapType(mapHeaderID) == MAP_TYPE_POKECENTER;
 }
 
-BOOL MapHeader_IsOutdoors(u32 headerID)
+BOOL MapHeader_IsOutdoors(enum MapHeaderID mapHeaderID)
 {
-    return MapHeader_GetMapType(headerID) == MAP_TYPE_TOWN_CITY
-        || MapHeader_GetMapType(headerID) == MAP_TYPE_OUTDOORS;
+    return MapHeader_GetMapType(mapHeaderID) == MAP_TYPE_TOWN_CITY
+        || MapHeader_GetMapType(mapHeaderID) == MAP_TYPE_OUTDOORS;
 }
 
-BOOL MapHeader_IsPokemonCenter2(u32 headerID)
+BOOL MapHeader_IsPokemonCenter2(enum MapHeaderID mapHeaderID)
 {
-    if (MapHeader_IsPokemonCenter(headerID)) {
+    if (MapHeader_IsPokemonCenter(mapHeaderID)) {
         return TRUE;
     }
 
     return FALSE;
 }
 
-BOOL MapHeader_IsUnionRoom(const u32 headerID)
+BOOL MapHeader_IsUnionRoom(const enum MapHeaderID mapHeaderID)
 {
-    return headerID == MAP_HEADER_UNION_ROOM;
+    return mapHeaderID == MAP_HEADER_UNION_ROOM;
 }
 
-BOOL MapHeader_HasFeebasTiles(const u32 headerID)
+BOOL MapHeader_HasFeebasTiles(const enum MapHeaderID mapHeaderID)
 {
-    return headerID == MAP_HEADER_MT_CORONET_B1F;
+    return mapHeaderID == MAP_HEADER_MT_CORONET_B1F;
 }
 
-BOOL MapHeader_IsTrophyGarden(const u32 headerID)
+BOOL MapHeader_IsTrophyGarden(const enum MapHeaderID mapHeaderID)
 {
-    return headerID == MAP_HEADER_TROPHY_GARDEN;
+    return mapHeaderID == MAP_HEADER_TROPHY_GARDEN;
 }
 
-BOOL MapHeader_IsAmitySquare(const u32 headerID)
+BOOL MapHeader_IsAmitySquare(const enum MapHeaderID mapHeaderID)
 {
-    return headerID == MAP_HEADER_AMITY_SQUARE;
+    return mapHeaderID == MAP_HEADER_AMITY_SQUARE;
 }
 
-BOOL MapHeader_IsAzureFluteAllowed(const u32 headerID)
+BOOL MapHeader_IsAzureFluteAllowed(const enum MapHeaderID mapHeaderID)
 {
-    if (headerID == MAP_HEADER_SPEAR_PILLAR || headerID == MAP_HEADER_SPEAR_PILLAR_DIALGA || headerID == MAP_HEADER_SPEAR_PILLAR_PALKIA) {
+    if (mapHeaderID == MAP_HEADER_SPEAR_PILLAR || mapHeaderID == MAP_HEADER_SPEAR_PILLAR_DIALGA || mapHeaderID == MAP_HEADER_SPEAR_PILLAR_PALKIA) {
         return TRUE;
     }
 
     return FALSE;
 }
 
-BOOL MapHeader_IsPokemonCenter2F(const u32 headerID)
+BOOL MapHeader_IsPokemonCenter2F(const enum MapHeaderID mapHeaderID)
 {
     static const u16 pokecenters2F[] = {
         MAP_HEADER_SANDGEM_TOWN_POKECENTER_2F,
@@ -240,7 +240,7 @@ BOOL MapHeader_IsPokemonCenter2F(const u32 headerID)
     int i;
 
     for (i = 0; i < NELEMS(pokecenters2F); i++) {
-        if (headerID == pokecenters2F[i]) {
+        if (mapHeaderID == pokecenters2F[i]) {
             return TRUE;
         }
     }
@@ -248,7 +248,7 @@ BOOL MapHeader_IsPokemonCenter2F(const u32 headerID)
     return FALSE;
 }
 
-enum EvolutionMethod MapHeader_GetMapEvolutionMethod(u32 headerID)
+enum EvolutionMethod MapHeader_GetMapEvolutionMethod(enum MapHeaderID mapHeaderID)
 {
     static const u16 mapEvolutionMethods[] = {
         MAP_HEADER_ROUTE_217,
@@ -296,7 +296,7 @@ enum EvolutionMethod MapHeader_GetMapEvolutionMethod(u32 headerID)
     };
 
     for (int i = 0; i < NELEMS(mapEvolutionMethods); i += 2) {
-        if (mapEvolutionMethods[i] == headerID) {
+        if (mapEvolutionMethods[i] == mapHeaderID) {
             return mapEvolutionMethods[i + 1];
         }
     }
diff --git a/src/map_header_data.c b/src/map_header_data.c
index 3429886dc4..6e46858701 100644
--- a/src/map_header_data.c
+++ b/src/map_header_data.c
@@ -5,6 +5,7 @@
 
 #include "constants/heap.h"
 #include "constants/versions.h"
+#include "generated/map_headers.h"
 
 #include "field/field_system.h"
 #include "overlay006/wild_encounters.h"
@@ -14,7 +15,7 @@
 #include "map_object.h"
 #include "narc.h"
 
-static void MapHeaderData_LoadEvents(MapHeaderData *data, int headerID);
+static void MapHeaderData_LoadEvents(MapHeaderData *data, enum MapHeaderID mapHeaderID);
 static void MapHeaderData_ParseEvents(MapHeaderData *data);
 static void MapHeaderData_LoadInitScripts(MapHeaderData *data, int headerID);
 
@@ -30,19 +31,19 @@ void MapHeaderData_Free(FieldSystem *fieldSystem)
     Heap_Free(fieldSystem->mapHeaderData);
 }
 
-void MapHeaderData_Load(FieldSystem *fieldSystem, int headerID)
+void MapHeaderData_Load(FieldSystem *fieldSystem, enum MapHeaderID mapHeaderID)
 {
     GF_ASSERT(fieldSystem->mapHeaderData != NULL);
 
-    MapHeaderData_LoadEvents(fieldSystem->mapHeaderData, headerID);
+    MapHeaderData_LoadEvents(fieldSystem->mapHeaderData, mapHeaderID);
     MapHeaderData_ParseEvents(fieldSystem->mapHeaderData);
-    MapHeaderData_LoadWildEncounters(&fieldSystem->mapHeaderData->wildEncounters, headerID);
-    MapHeaderData_LoadInitScripts(fieldSystem->mapHeaderData, headerID);
+    MapHeaderData_LoadWildEncounters(&fieldSystem->mapHeaderData->wildEncounters, mapHeaderID);
+    MapHeaderData_LoadInitScripts(fieldSystem->mapHeaderData, mapHeaderID);
 }
 
-static void MapHeaderData_LoadEvents(MapHeaderData *data, int headerID)
+static void MapHeaderData_LoadEvents(MapHeaderData *data, enum MapHeaderID mapHeaderID)
 {
-    int eventsID = MapHeader_GetEventsArchiveID(headerID);
+    int eventsID = MapHeader_GetEventsArchiveID(mapHeaderID);
     GF_ASSERT(NARC_GetMemberSizeByIndexPair(NARC_INDEX_FIELDDATA__EVENTDATA__ZONE_EVENT, eventsID) < sizeof(data->tmpEventsBuf));
     NARC_ReadWholeMemberByIndexPair(data->tmpEventsBuf, NARC_INDEX_FIELDDATA__EVENTDATA__ZONE_EVENT, eventsID);
 }
@@ -54,7 +55,7 @@ void sub_0203A418(FieldSystem *fieldSystem)
     GF_ASSERT(fieldSystem->mapHeaderData != NULL);
 
     if (numObjectEvents != 0) {
-        sub_02062068(fieldSystem->mapObjMan, fieldSystem->location->mapId, numObjectEvents, fieldSystem->mapHeaderData->objectEvents);
+        sub_02062068(fieldSystem->mapObjMan, fieldSystem->location->mapHeaderID, numObjectEvents, fieldSystem->mapHeaderData->objectEvents);
     }
 }
 
@@ -214,14 +215,14 @@ static void MapHeaderData_ParseEvents(MapHeaderData *data)
     CONSUME_EVENTS(CoordEvent, data->coordEvents, data->numCoordEvents);
 }
 
-void MapHeaderData_LoadWildEncounters(WildEncounters *data, int headerID)
+void MapHeaderData_LoadWildEncounters(WildEncounters *data, enum MapHeaderID mapHeaderID)
 {
     memset(data, 0, sizeof(WildEncounters));
-    if (MapHeader_HasWildEncounters(headerID)) {
+    if (MapHeader_HasWildEncounters(mapHeaderID)) {
         enum NarcID narcID = (GAME_VERSION == VERSION_DIAMOND || GAME_VERSION == VERSION_PLATINUM)
             ? NARC_INDEX_FIELDDATA__ENCOUNTDATA__PL_ENC_DATA
             : NARC_INDEX_FIELDDATA__ENCOUNTDATA__P_ENC_DATA;
-        NARC_ReadWholeMemberByIndexPair(data, narcID, MapHeader_GetWildEncountersArchiveID(headerID));
+        NARC_ReadWholeMemberByIndexPair(data, narcID, MapHeader_GetWildEncountersArchiveID(mapHeaderID));
     }
 }
 
diff --git a/src/map_object.c b/src/map_object.c
index eba057cfe4..ab6b913379 100644
--- a/src/map_object.c
+++ b/src/map_object.c
@@ -54,7 +54,7 @@ typedef struct MapObject {
     u32 status;
     u32 unk_04;
     u32 localID;
-    u32 mapID;
+    enum MapHeaderID mapHeaderID;
     u32 graphicsID;
     u32 movementType;
     u32 trainerType;
@@ -135,8 +135,8 @@ static int MapObject_GetFieldSystemGraphicsID(FieldSystem *fieldSystem, int para
 static void sub_02062648(MapObject *mapObj);
 static void sub_02062660(MapObject *mapObj);
 static void sub_02062670(MapObject *mapObj);
-static void sub_020626D0(MapObject *mapObj, const ObjectEvent *objectEvent, int mapID);
-static void sub_02062714(MapObject *mapObj, int mapID, const ObjectEvent *objectEvent);
+static void sub_020626D0(MapObject *mapObj, const ObjectEvent *objectEvent, enum MapHeaderID mapHeaderID);
+static void sub_02062714(MapObject *mapObj, enum MapHeaderID mapHeaderID, const ObjectEvent *objectEvent);
 static void MapObjectTask_Move(SysTask *task, void *param1);
 static void MapObjectTask_Draw(MapObject *mapObj);
 static MapObjectManager *MapObjectMan_Deconst(const MapObjectManager *mapObjMan);
@@ -176,18 +176,18 @@ void MapObjectMan_Delete(MapObjectManager *mapObjMan)
     Heap_FreeExplicit(HEAP_ID_FIELD2, mapObjMan);
 }
 
-void sub_0206184C(MapObjectManager *mapObjMan, int mapID, int param2, int objEventCount, const ObjectEvent *objectEvent)
+void sub_0206184C(MapObjectManager *mapObjMan, enum MapHeaderID oldMapHeaderID, enum MapHeaderID newMapHeaderID, int objEventCount, const ObjectEvent *objectEvent)
 {
-    int v0, maxObjects = MapObjectMan_GetMaxObjects(mapObjMan);
+    int maxObjects = MapObjectMan_GetMaxObjects(mapObjMan);
     MapObject *mapObj = MapObjectMan_GetMapObject(mapObjMan);
 
     while (maxObjects) {
         if (sub_02062CF8(mapObj) == TRUE) {
-            v0 = sub_0206244C(mapObj, param2, objEventCount, objectEvent);
+            int v0 = sub_0206244C(mapObj, newMapHeaderID, objEventCount, objectEvent);
 
             switch (v0) {
             case 0:
-                if (MapObject_GetMapID(mapObj) != param2 && !MapObject_CheckStatusFlag(mapObj, MAP_OBJ_STATUS_PERSISTENT)) {
+                if (MapObject_GetMapHeaderID(mapObj) != newMapHeaderID && !MapObject_CheckStatusFlag(mapObj, MAP_OBJ_STATUS_PERSISTENT)) {
                     MapObject_Delete(mapObj);
                 }
                 break;
@@ -225,7 +225,7 @@ static MapObjectManager *MapObjectMan_Alloc(int maxObjs)
     return mapObjMan;
 }
 
-MapObject *MapObjectMan_AddMapObjectFromHeader(const MapObjectManager *mapObjMan, const ObjectEvent *objectEvent, int mapID)
+MapObject *MapObjectMan_AddMapObjectFromHeader(const MapObjectManager *mapObjMan, const ObjectEvent *objectEvent, enum MapHeaderID mapHeaderID)
 {
     MapObject *mapObj;
     ObjectEvent v1 = *objectEvent;
@@ -234,10 +234,10 @@ MapObject *MapObjectMan_AddMapObjectFromHeader(const MapObjectManager *mapObjMan
     int localID = ObjectEvent_GetLocalID(v2);
 
     if (ObjectEvent_HasNoScript(v2) == FALSE) {
-        mapObj = sub_02062154(mapObjMan, localID, mapID);
+        mapObj = sub_02062154(mapObjMan, localID, mapHeaderID);
 
         if (mapObj != NULL) {
-            sub_020626D0(mapObj, v2, mapID);
+            sub_020626D0(mapObj, v2, mapHeaderID);
 
             return mapObj;
         }
@@ -245,7 +245,7 @@ MapObject *MapObjectMan_AddMapObjectFromHeader(const MapObjectManager *mapObjMan
         mapObj = sub_020624CC(mapObjMan, localID, ObjectEvent_GetHiddenFlagNoScript(v2));
 
         if (mapObj != NULL) {
-            sub_02062714(mapObj, mapID, v2);
+            sub_02062714(mapObj, mapHeaderID, v2);
             return mapObj;
         }
     }
@@ -258,7 +258,7 @@ MapObject *MapObjectMan_AddMapObjectFromHeader(const MapObjectManager *mapObjMan
 
     sub_020621E8(mapObj, v2, MapObjectMan_FieldSystem(mapObjMan));
     sub_0206234C(mapObj, mapObjMan);
-    MapObject_SetMapID(mapObj, mapID);
+    MapObject_SetMapHeaderID(mapObj, mapHeaderID);
     sub_02062660(mapObj);
     sub_02062670(mapObj);
     MapObject_SetStatusFlagOn(mapObj, MAP_OBJ_STATUS_START_MOVEMENT);
@@ -268,7 +268,7 @@ MapObject *MapObjectMan_AddMapObjectFromHeader(const MapObjectManager *mapObjMan
     return mapObj;
 }
 
-MapObject *MapObjectMan_AddMapObject(const MapObjectManager *mapObjMan, int x, int z, int initialDir, int graphicsID, int movementType, int mapID)
+MapObject *MapObjectMan_AddMapObject(const MapObjectManager *mapObjMan, int x, int z, int initialDir, int graphicsID, int movementType, enum MapHeaderID mapHeaderID)
 {
     ObjectEvent objectEvent;
     MapObject *mapObj;
@@ -289,12 +289,12 @@ MapObject *MapObjectMan_AddMapObject(const MapObjectManager *mapObjMan, int x, i
     ObjectEvent_SetZ(&objectEvent, z);
     ObjectEvent_SetY(&objectEvent, 0);
 
-    mapObj = MapObjectMan_AddMapObjectFromHeader(mapObjMan, &objectEvent, mapID);
+    mapObj = MapObjectMan_AddMapObjectFromHeader(mapObjMan, &objectEvent, mapHeaderID);
 
     return mapObj;
 }
 
-MapObject *MapObjectMan_AddMapObjectFromLocalID(const MapObjectManager *mapObjMan, int localID, int objEventCount, int mapID, const ObjectEvent *objectEvent)
+MapObject *MapObjectMan_AddMapObjectFromLocalID(const MapObjectManager *mapObjMan, int localID, int objEventCount, enum MapHeaderID mapHeaderID, const ObjectEvent *objectEvent)
 {
     MapObject *mapObj = NULL;
     const ObjectEvent *v1 = sub_020631A4(localID, objEventCount, objectEvent);
@@ -304,7 +304,7 @@ MapObject *MapObjectMan_AddMapObjectFromLocalID(const MapObjectManager *mapObjMa
         FieldSystem *fieldSystem = MapObjectMan_FieldSystem(mapObjMan);
 
         if (!FieldSystem_CheckFlag(fieldSystem, hiddenFlag)) {
-            mapObj = MapObjectMan_AddMapObjectFromHeader(mapObjMan, v1, mapID);
+            mapObj = MapObjectMan_AddMapObjectFromHeader(mapObjMan, v1, mapHeaderID);
         }
     }
 
@@ -470,7 +470,7 @@ static void MapObject_Save(FieldSystem *fieldSystem, MapObject *mapObj, MapObjec
     mapObjSave->status = MapObject_GetStatus(mapObj);
     mapObjSave->unk_04 = sub_020628EC(mapObj);
     mapObjSave->localID = MapObject_GetLocalID(mapObj);
-    mapObjSave->mapID = MapObject_GetMapID(mapObj);
+    mapObjSave->mapID = MapObject_GetMapHeaderID(mapObj);
     mapObjSave->graphicsID = MapObject_GetGraphicsID(mapObj);
     mapObjSave->movementType = MapObject_GetMovementType(mapObj);
     mapObjSave->trainerType = MapObject_GetTrainerType(mapObj);
@@ -519,7 +519,7 @@ static void MapObject_LoadSave(MapObject *mapObj, MapObjectSave *mapObjSave)
     MapObject_SetStatus(mapObj, mapObjSave->status);
     sub_020628E8(mapObj, mapObjSave->unk_04);
     MapObject_SetLocalID(mapObj, mapObjSave->localID);
-    MapObject_SetMapID(mapObj, mapObjSave->mapID);
+    MapObject_SetMapHeaderID(mapObj, mapObjSave->mapID);
     MapObject_SetGraphicsID(mapObj, mapObjSave->graphicsID);
     MapObject_SetMovementType(mapObj, mapObjSave->movementType);
     MapObject_SetTrainerType(mapObj, mapObjSave->trainerType);
@@ -590,25 +590,21 @@ static void sub_02062010(MapObject *mapObj)
     MapObject_SetPos(mapObj, &v1);
 }
 
-void sub_02062068(const MapObjectManager *mapObjMan, int param1, int param2, const ObjectEvent *objectEvent)
+void sub_02062068(const MapObjectManager *mapObjMan, enum MapHeaderID mapHeaderID, u32 numObjectEvents, const ObjectEvent *objectEvent)
 {
-    int v0;
-    ObjectEvent *v1;
-    UnkStruct_020620C4 *v2;
+    GF_ASSERT(numObjectEvents);
 
-    GF_ASSERT(param2);
-
-    v0 = sizeof(ObjectEvent) * param2;
-    v1 = Heap_AllocAtEnd(HEAP_ID_FIELD2, v0);
+    int v0 = sizeof(ObjectEvent) * numObjectEvents;
+    ObjectEvent *v1 = Heap_AllocAtEnd(HEAP_ID_FIELD2, v0);
 
     GF_ASSERT(v1 != NULL);
     memcpy(v1, objectEvent, v0);
 
-    v2 = Heap_AllocAtEnd(HEAP_ID_FIELD2, sizeof(UnkStruct_020620C4));
+    UnkStruct_020620C4 *v2 = Heap_AllocAtEnd(HEAP_ID_FIELD2, sizeof(UnkStruct_020620C4));
     GF_ASSERT(v2 != NULL);
 
-    v2->unk_00 = param1;
-    v2->unk_04 = param2;
+    v2->unk_00 = mapHeaderID;
+    v2->unk_04 = numObjectEvents;
     v2->unk_08 = 0;
     v2->mapObjMan = mapObjMan;
     v2->objectEvent = v1;
@@ -797,7 +793,7 @@ static int sub_0206244C(const MapObject *mapObj, int param1, int objEventCount,
                     if (sub_02062C18(mapObj) == flag) {
                         return 1;
                     }
-                } else if (MapObject_GetMapID(mapObj) == flag) {
+                } else if (MapObject_GetMapHeaderID(mapObj) == flag) {
                     return 2;
                 }
             } else if (sub_02062E94(mapObj) == TRUE && sub_02062C18(mapObj) == param1) {
@@ -818,7 +814,7 @@ static MapObject *sub_020624CC(const MapObjectManager *mapObjMan, int localID, i
     MapObject *mapObj;
 
     while (MapObjectMan_FindObjectWithStatus(mapObjMan, &mapObj, &v0, MAP_OBJ_STATUS_0) == TRUE) {
-        if (MapObject_GetLocalID(mapObj) == localID && MapObject_GetMapID(mapObj) == flag) {
+        if (MapObject_GetLocalID(mapObj) == localID && MapObject_GetMapHeaderID(mapObj) == flag) {
             return mapObj;
         }
     }
@@ -961,24 +957,24 @@ int MapObject_HasNoScript(const MapObject *mapObj)
     return FALSE;
 }
 
-static void sub_020626D0(MapObject *mapObj, const ObjectEvent *objectEvent, int mapID)
+static void sub_020626D0(MapObject *mapObj, const ObjectEvent *objectEvent, enum MapHeaderID mapHeaderID)
 {
     GF_ASSERT(sub_02062E94(mapObj) == TRUE);
 
     sub_02062E78(mapObj, 0);
-    MapObject_SetMapID(mapObj, mapID);
+    MapObject_SetMapHeaderID(mapObj, mapHeaderID);
     MapObject_SetScript(mapObj, ObjectEvent_GetScript(objectEvent));
     MapObject_SetFlag(mapObj, ObjectEvent_GetHiddenFlag(objectEvent));
 }
 
-static void sub_02062714(MapObject *mapObj, int mapID, const ObjectEvent *objectEvent)
+static void sub_02062714(MapObject *mapObj, enum MapHeaderID mapHeaderID, const ObjectEvent *objectEvent)
 {
     GF_ASSERT(ObjectEvent_HasNoScript(objectEvent) == TRUE);
 
     sub_02062E78(mapObj, 1);
     MapObject_SetScript(mapObj, ObjectEvent_GetScript(objectEvent));
     MapObject_SetFlag(mapObj, ObjectEvent_GetHiddenFlagNoScript(objectEvent));
-    MapObject_SetMapID(mapObj, mapID);
+    MapObject_SetMapHeaderID(mapObj, mapHeaderID);
 }
 
 int MapObject_CalculateTaskPriority(const MapObject *mapObj, int priority)
@@ -989,7 +985,7 @@ int MapObject_CalculateTaskPriority(const MapObject *mapObj, int priority)
     return result;
 }
 
-int sub_02062764(const MapObject *mapObj, int param1, int param2)
+int sub_02062764(const MapObject *mapObj, int param1, enum MapHeaderID param2)
 {
     if (!MapObject_CheckStatusFlag(mapObj, MAP_OBJ_STATUS_0)) {
         return FALSE;
@@ -999,7 +995,7 @@ int sub_02062764(const MapObject *mapObj, int param1, int param2)
         return FALSE;
     }
 
-    if (MapObject_GetMapID(mapObj) != param2) {
+    if (MapObject_GetMapHeaderID(mapObj) != param2) {
         if (sub_02062E94(mapObj) == FALSE) {
             return FALSE;
         }
@@ -1012,7 +1008,7 @@ int sub_02062764(const MapObject *mapObj, int param1, int param2)
     return TRUE;
 }
 
-int sub_020627B4(const MapObject *mapObj, int param1, int param2, int param3)
+int sub_020627B4(const MapObject *mapObj, int param1, int param2, enum MapHeaderID param3)
 {
     if (!MapObject_CheckStatusFlag(mapObj, MAP_OBJ_STATUS_0)) {
         return 0;
@@ -1217,14 +1213,14 @@ u32 MapObject_GetLocalID(const MapObject *mapObj)
     return mapObj->localID;
 }
 
-void MapObject_SetMapID(MapObject *mapObj, int mapID)
+void MapObject_SetMapHeaderID(MapObject *mapObj, enum MapHeaderID mapHeaderID)
 {
-    mapObj->mapID = mapID;
+    mapObj->mapHeaderID = mapHeaderID;
 }
 
-int MapObject_GetMapID(const MapObject *mapObj)
+enum MapHeaderID MapObject_GetMapHeaderID(const MapObject *mapObj)
 {
-    return mapObj->mapID;
+    return mapObj->mapHeaderID;
 }
 
 void MapObject_SetGraphicsID(MapObject *mapObj, u32 graphicsID)
diff --git a/src/meson.build b/src/meson.build
index 0c75ffea1d..75327e6295 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -262,7 +262,7 @@ pokeplatinum_c = files(
     'cutscenes/boat_cutscene/boat_cutscene.c',
     'tv_segment.c',
     'rankings_machine.c',
-    'unk_02070428.c',
+    'field_map_change_flags.c',
     'field_move_tasks.c',
     'unk_020711C8.c',
     'overworld_anim_manager.c',
diff --git a/src/overlay005/berry_patch_effects.c b/src/overlay005/berry_patch_effects.c
index 8a7e2eb465..a367ed61f5 100644
--- a/src/overlay005/berry_patch_effects.c
+++ b/src/overlay005/berry_patch_effects.c
@@ -35,7 +35,7 @@ typedef struct BerryPatchMoistureEffectContext {
 
 typedef struct BerryPatchMoistureEffect {
     int localID;
-    int mapID;
+    enum MapHeaderID mapHeaderID;
     BOOL isHidden;
     int moistureLevel;
     BerryPatchMoistureEffectContext context;
@@ -139,7 +139,7 @@ static BOOL BerryPatchMoistureEffect_Init(OverworldAnimManager *effect, void *co
 
     moistureEffect->context = *effectContext;
     moistureEffect->localID = MapObject_GetLocalID(moistureEffect->context.mapObject);
-    moistureEffect->mapID = MapObject_GetMapID(moistureEffect->context.mapObject);
+    moistureEffect->mapHeaderID = MapObject_GetMapHeaderID(moistureEffect->context.mapObject);
 
     return TRUE;
 }
@@ -154,7 +154,7 @@ static void BerryPatchMoistureEffect_Update(OverworldAnimManager *effectTask, vo
     BerryPatchMoistureEffect *berryPatchEffect = effectData;
     MapObject *mapObject = berryPatchEffect->context.mapObject;
 
-    if (!sub_02062764(mapObject, berryPatchEffect->localID, berryPatchEffect->mapID)) {
+    if (!sub_02062764(mapObject, berryPatchEffect->localID, berryPatchEffect->mapHeaderID)) {
         FieldEffectManager_FinishAnimManager(effectTask);
         return;
     }
diff --git a/src/overlay005/field_control.c b/src/overlay005/field_control.c
index 7d5a761e4f..54a9e7b753 100644
--- a/src/overlay005/field_control.c
+++ b/src/overlay005/field_control.c
@@ -555,7 +555,7 @@ static BOOL Field_CheckWildEncounter(FieldSystem *fieldSystem)
         }
     }
 
-    return MapHeader_HasWildEncounters(fieldSystem->location->mapId) && WildEncounters_TryWildEncounter(fieldSystem) == TRUE;
+    return MapHeader_HasWildEncounters(fieldSystem->location->mapHeaderID) && WildEncounters_TryWildEncounter(fieldSystem) == TRUE;
 }
 
 static BOOL Field_CheckMapTransition(FieldSystem *fieldSystem, const FieldInput *input)
@@ -588,7 +588,7 @@ static BOOL Field_CheckMapTransition(FieldSystem *fieldSystem, const FieldInput
                 HearthomeGym_CheckIfEnteredIncorrectDoor(fieldSystem, playerX, playerZ, &transitionDir);
             }
 
-            sub_02056BDC(fieldSystem, nextMap.mapId, nextMap.warpId, 0, 0, transitionDir, 1);
+            sub_02056BDC(fieldSystem, nextMap.mapHeaderID, nextMap.warpId, 0, 0, transitionDir, 1);
 
             return TRUE;
         }
@@ -635,14 +635,14 @@ static BOOL Field_CheckMapTransition(FieldSystem *fieldSystem, const FieldInput
     } else if (TileBehavior_IsWarpEntranceEast(tileBehavior) || TileBehavior_IsWarpEast(tileBehavior)
         || TileBehavior_IsWarpEntranceWest(tileBehavior) || TileBehavior_IsWarpWest(tileBehavior)
         || TileBehavior_IsWarpEntranceSouth(tileBehavior) || TileBehavior_IsWarpSouth(tileBehavior)) {
-        sub_02056C18(fieldSystem, nextMap.mapId, nextMap.warpId, 0, 0, input->transitionDir);
+        sub_02056C18(fieldSystem, nextMap.mapHeaderID, nextMap.warpId, 0, 0, input->transitionDir);
         return TRUE;
     } else {
         return FALSE;
     }
 
     // these statements are unreachable, but required for matching
-    sub_02056BDC(fieldSystem, nextMap.mapId, nextMap.warpId, 0, 0, input->transitionDir, transitionType);
+    sub_02056BDC(fieldSystem, nextMap.mapHeaderID, nextMap.warpId, 0, 0, input->transitionDir, transitionType);
 
     return TRUE;
 }
@@ -796,7 +796,7 @@ static BOOL Field_CheckTransition(FieldSystem *fieldSystem, const int playerX, c
             return FALSE;
         }
 
-        sub_02056BDC(fieldSystem, nextMap.mapId, nextMap.warpId, 0, 0, playerDir, 2);
+        sub_02056BDC(fieldSystem, nextMap.mapHeaderID, nextMap.warpId, 0, 0, playerDir, 2);
         return TRUE;
     } else if (TileBehavior_IsEscalator(curTileBehavior) == TRUE) {
         int playerDir = PlayerAvatar_GetFacingDir(fieldSystem->playerAvatar);
@@ -806,17 +806,17 @@ static BOOL Field_CheckTransition(FieldSystem *fieldSystem, const int playerX, c
             return FALSE;
         }
 
-        sub_02056BDC(fieldSystem, nextMap.mapId, nextMap.warpId, 0, 0, playerDir, 2);
+        sub_02056BDC(fieldSystem, nextMap.mapHeaderID, nextMap.warpId, 0, 0, playerDir, 2);
         return TRUE;
     }
 
     if (TileBehavior_IsWarpEntranceNorth(curTileBehavior) || TileBehavior_IsWarpNorth(curTileBehavior)) {
-        sub_02056C18(fieldSystem, nextMap.mapId, nextMap.warpId, 0, 0, 0);
+        sub_02056C18(fieldSystem, nextMap.mapHeaderID, nextMap.warpId, 0, 0, 0);
         return TRUE;
     }
 
     if (TileBehavior_IsWarpPanel(curTileBehavior)) {
-        FieldSystem_StartMapChangeWarpTask(fieldSystem, nextMap.mapId, nextMap.warpId);
+        FieldSystem_StartMapChangeWarpTask(fieldSystem, nextMap.mapHeaderID, nextMap.warpId);
         return TRUE;
     }
 
@@ -883,7 +883,7 @@ static void Field_CalculateFriendship(FieldSystem *fieldSystem)
     // C99-style declarations don't match
     int i, partyCount;
     Party *party = SaveData_GetParty(fieldSystem->saveData);
-    u16 mapID = MapHeader_GetMapLabelTextID(fieldSystem->location->mapId);
+    u16 mapID = MapHeader_GetMapLabelTextID(fieldSystem->location->mapHeaderID);
 
     partyCount = Party_GetCurrentCount(party);
 
@@ -905,7 +905,7 @@ static BOOL Field_UpdatePoison(FieldSystem *fieldSystem)
         return FALSE;
     }
 
-    switch (Pokemon_DoPoisonDamage(party, MapHeader_GetMapLabelTextID(fieldSystem->location->mapId))) {
+    switch (Pokemon_DoPoisonDamage(party, MapHeader_GetMapLabelTextID(fieldSystem->location->mapHeaderID))) {
     case FLDPSN_NONE:
         return FALSE;
     case FLDPSN_POISONED:
@@ -994,28 +994,27 @@ static u8 Field_NextTileBehavior(const FieldSystem *fieldSystem)
 
 static BOOL Field_MapConnection(const FieldSystem *fieldSystem, int playerX, int playerZ, Location *nextMap)
 {
-    const WarpEvent *v0;
-    int v1 = MapHeaderData_GetIndexOfWarpEventAtPos(fieldSystem, playerX, playerZ);
+    int eventIndex = MapHeaderData_GetIndexOfWarpEventAtPos(fieldSystem, playerX, playerZ);
 
-    if (v1 == -1) {
+    if (eventIndex == -1) {
         return FALSE;
     }
 
-    v0 = MapHeaderData_GetWarpEventByIndex(fieldSystem, v1);
+    const WarpEvent *warpEvent = MapHeaderData_GetWarpEventByIndex(fieldSystem, eventIndex);
 
-    if (v0 == NULL) {
+    if (warpEvent == NULL) {
         return FALSE;
     }
 
-    if (v0->destWarpID == 0x100) {
-        GF_ASSERT(v0->destHeaderID == 0xfff);
+    if (warpEvent->destWarpID == 0x100) {
+        GF_ASSERT(warpEvent->destHeaderID == 0xfff);
         *nextMap = *(FieldOverworldState_GetSpecialLocation(SaveData_GetFieldOverworldState(fieldSystem->saveData)));
     } else {
-        Location_Set(nextMap, v0->destHeaderID, v0->destWarpID, v0->x, v0->z, 1);
+        Location_Set(nextMap, warpEvent->destHeaderID, warpEvent->destWarpID, warpEvent->x, warpEvent->z, 1);
     }
 
-    Location *v2 = FieldOverworldState_GetEntranceLocation(SaveData_GetFieldOverworldState(fieldSystem->saveData));
-    Location_Set(v2, fieldSystem->location->mapId, v1, playerX, playerZ, PlayerAvatar_GetFacingDir(fieldSystem->playerAvatar));
+    Location *entrance = FieldOverworldState_GetEntranceLocation(SaveData_GetFieldOverworldState(fieldSystem->saveData));
+    Location_Set(entrance, fieldSystem->location->mapHeaderID, eventIndex, playerX, playerZ, PlayerAvatar_GetFacingDir(fieldSystem->playerAvatar));
 
     return TRUE;
 }
@@ -1034,7 +1033,7 @@ static void Field_SetMapConnection(FieldSystem *fieldSystem, const int playerX,
         (nextMap->z)++;
     }
 
-    nextMap->mapId = fieldSystem->location->mapId;
+    nextMap->mapHeaderID = fieldSystem->location->mapHeaderID;
     nextMap->warpId = WARP_ID_NONE;
 }
 
@@ -1046,15 +1045,15 @@ static void Field_TrySetMapConnection(FieldSystem *fieldSystem)
     Location nextMap;
 
     if (Field_MapConnection(fieldSystem, playerX, playerZ, &nextMap)) {
-        if (MapHeader_IsOnMainMatrix(fieldSystem->location->mapId) == TRUE && MapHeader_IsOnMainMatrix(nextMap.mapId) == FALSE) {
+        if (MapHeader_IsOnMainMatrix(fieldSystem->location->mapHeaderID) == TRUE && MapHeader_IsOnMainMatrix(nextMap.mapHeaderID) == FALSE) {
             Field_SetMapConnection(fieldSystem, playerX, playerZ, PlayerAvatar_GetFacingDir(fieldSystem->playerAvatar));
         }
     } else {
         Field_Step(fieldSystem, &playerX, &playerZ);
 
         if (Field_MapConnection(fieldSystem, playerX, playerZ, &nextMap)
-            && MapHeader_IsOnMainMatrix(fieldSystem->location->mapId) == TRUE
-            && MapHeader_IsOnMainMatrix(nextMap.mapId) == FALSE) {
+            && MapHeader_IsOnMainMatrix(fieldSystem->location->mapHeaderID) == TRUE
+            && MapHeader_IsOnMainMatrix(nextMap.mapHeaderID) == FALSE) {
 
             Field_SetMapConnection(fieldSystem, playerX, playerZ, PlayerAvatar_GetFacingDir(fieldSystem->playerAvatar));
         }
diff --git a/src/overlay005/fieldmap.c b/src/overlay005/fieldmap.c
index 40fbf445d6..874cadf83a 100644
--- a/src/overlay005/fieldmap.c
+++ b/src/overlay005/fieldmap.c
@@ -220,7 +220,7 @@ static BOOL FieldMap_Init(ApplicationManager *appMan, int *state)
             ov5_021D5F24(fieldSystem->unk_04->unk_0C, weather);
         }
 
-        FieldBGM_PlayEffectiveForMapHeader(fieldSystem, fieldSystem->location->mapId);
+        FieldBGM_PlayEffectiveForMapHeader(fieldSystem, fieldSystem->location->mapHeaderID);
         FieldSystem_RunInitScript(fieldSystem, INIT_SCRIPT_ON_RESUME);
 
         fieldSystem->unk_04->hBlankSystem = HBlankSystem_New(HEAP_ID_FIELD1);
@@ -403,26 +403,26 @@ static BOOL FieldMap_ChangeZone(FieldSystem *fieldSystem)
     int x = (PlayerAvatar_GetXPos(fieldSystem->playerAvatar) - LandDataManager_GetOffsetTileX(fieldSystem->landDataMan)) / MAP_TILES_COUNT_X;
     int y = (PlayerAvatar_GetZPos(fieldSystem->playerAvatar) - LandDataManager_GetOffsetTileZ(fieldSystem->landDataMan)) / MAP_TILES_COUNT_Z;
 
-    u32 newMapID = MapMatrix_GetMapHeaderIDAtCoords(fieldSystem->mapMatrix, x, y);
-    u32 oldMapID = fieldSystem->location->mapId;
-    if (newMapID == oldMapID) {
+    enum MapHeaderID newMapHeaderID = MapMatrix_GetMapHeaderIDAtCoords(fieldSystem->mapMatrix, x, y);
+    enum MapHeaderID oldMapHeaderID = fieldSystem->location->mapHeaderID;
+    if (newMapHeaderID == oldMapHeaderID) {
         return FALSE;
     }
 
     FieldOverworldState *fieldState = SaveData_GetFieldOverworldState(fieldSystem->saveData);
 
-    fieldSystem->location->mapId = newMapID;
+    fieldSystem->location->mapHeaderID = newMapHeaderID;
 
-    MapHeaderData_Load(fieldSystem, newMapID);
+    MapHeaderData_Load(fieldSystem, newMapHeaderID);
     FieldMapChange_UpdateGameData(fieldSystem, 1);
 
     int objEventCount = MapHeaderData_GetNumObjectEvents(fieldSystem);
     const ObjectEvent *objEventList = MapHeaderData_GetObjectEvents(fieldSystem);
 
-    sub_0206184C(fieldSystem->mapObjMan, oldMapID, newMapID, objEventCount, objEventList);
+    sub_0206184C(fieldSystem->mapObjMan, oldMapHeaderID, newMapHeaderID, objEventCount, objEventList);
 
     RadarChain_Clear(fieldSystem->chain);
-    FieldBGM_TryFadeOut(fieldSystem, FieldBGM_GetEffective(fieldSystem, fieldSystem->location->mapId), 1);
+    FieldBGM_TryFadeOut(fieldSystem, FieldBGM_GetEffective(fieldSystem, fieldSystem->location->mapHeaderID), 1);
     sub_0203A418(fieldSystem);
 
     if (fieldSystem->unk_04->unk_0C != NULL) {
@@ -430,9 +430,9 @@ static BOOL FieldMap_ChangeZone(FieldSystem *fieldSystem)
             fieldSystem->unk_04->unk_0C, FieldOverworldState_GetWeather(fieldState));
     }
 
-    int oldMapLabelTextID = MapHeader_GetMapLabelTextID(oldMapID);
-    int newMapLabelTextID = MapHeader_GetMapLabelTextID(newMapID);
-    int mapLabelWindowID = MapHeader_GetMapLabelWindowID(newMapID);
+    int oldMapLabelTextID = MapHeader_GetMapLabelTextID(oldMapHeaderID);
+    int newMapLabelTextID = MapHeader_GetMapLabelTextID(newMapHeaderID);
+    int mapLabelWindowID = MapHeader_GetMapLabelWindowID(newMapHeaderID);
 
     if (oldMapLabelTextID != newMapLabelTextID) {
         if (mapLabelWindowID != 0) {
@@ -445,22 +445,22 @@ static BOOL FieldMap_ChangeZone(FieldSystem *fieldSystem)
     return TRUE;
 }
 
-void FieldMap_ChangeZoneDistortionWorld(FieldSystem *fieldSystem, u32 mapId)
+void FieldMap_ChangeZoneDistortionWorld(FieldSystem *fieldSystem, enum MapHeaderID mapHeaderID)
 {
-    u32 oldMapId = fieldSystem->location->mapId;
+    enum MapHeaderID oldMapHeaderID = fieldSystem->location->mapHeaderID;
     FieldOverworldState *fieldState = SaveData_GetFieldOverworldState(fieldSystem->saveData);
 
-    fieldSystem->location->mapId = mapId;
+    fieldSystem->location->mapHeaderID = mapHeaderID;
 
-    MapHeaderData_Load(fieldSystem, mapId);
+    MapHeaderData_Load(fieldSystem, mapHeaderID);
     FieldMapChange_UpdateGameDataDistortionWorld(fieldSystem, 1);
 
-    int objEventCount = MapHeaderData_GetNumObjectEvents(fieldSystem);
+    u32 objEventCount = MapHeaderData_GetNumObjectEvents(fieldSystem);
     const ObjectEvent *objEventList = MapHeaderData_GetObjectEvents(fieldSystem);
 
-    sub_0206184C(fieldSystem->mapObjMan, oldMapId, mapId, objEventCount, objEventList);
+    sub_0206184C(fieldSystem->mapObjMan, oldMapHeaderID, mapHeaderID, objEventCount, objEventList);
 
-    FieldBGM_TryFadeOut(fieldSystem, FieldBGM_GetEffective(fieldSystem, fieldSystem->location->mapId), 1);
+    FieldBGM_TryFadeOut(fieldSystem, FieldBGM_GetEffective(fieldSystem, fieldSystem->location->mapHeaderID), 1);
     sub_0203A418(fieldSystem);
 
     if (fieldSystem->unk_04->unk_0C != NULL) {
@@ -500,7 +500,7 @@ static void ov5_021D134C(FieldSystem *fieldSystem, u8 param1)
 
 static void ov5_021D13B4(FieldSystem *fieldSystem)
 {
-    if (MapHeader_IsOnMainMatrix(fieldSystem->location->mapId) == 0) {
+    if (MapHeader_IsOnMainMatrix(fieldSystem->location->mapHeaderID) == 0) {
         return;
     }
 
@@ -767,9 +767,9 @@ static void InitGraphicsAndManagers(FieldSystem *fieldSystem)
     fieldSystem->mapPropAnimMan = MapPropAnimationManager_New();
     fieldSystem->mapPropOneShotAnimMan = MapPropOneShotAnimationManager_New();
 
-    u16 areaDataArchiveID = MapHeader_GetAreaDataArchiveID(fieldSystem->location->mapId);
+    u16 areaDataArchiveID = MapHeader_GetAreaDataArchiveID(fieldSystem->location->mapHeaderID);
     fieldSystem->areaDataManager = AreaDataManager_Alloc(areaDataArchiveID, fieldSystem->mapPropAnimMan);
-    u16 preloadedMapObjectsArchiveID = MapHeader_GetPreloadedMapObjectsArchiveID(fieldSystem->location->mapId);
+    u16 preloadedMapObjectsArchiveID = MapHeader_GetPreloadedMapObjectsArchiveID(fieldSystem->location->mapHeaderID);
 
     GF_ASSERT(fieldSystem->mapObjectsToPreload == NULL);
     fieldSystem->mapObjectsToPreload = FetchMapObjectsToPreload(HEAP_ID_FIELD1, preloadedMapObjectsArchiveID);
@@ -782,7 +782,7 @@ static void FieldSystem_InitLandManager(FieldSystem *fieldSystem)
     if (FieldMap_InDistortionWorld(fieldSystem) == TRUE) {
         int v0 = 0, v1 = 0, v2 = 0;
 
-        DistWorld_LoadFloorOffsets(fieldSystem->location->mapId, &v0, &v1, &v2);
+        DistWorld_LoadFloorOffsets(fieldSystem->location->mapHeaderID, &v0, &v1, &v2);
         LandDataManager_DistortionWorldSetOffsets(fieldSystem->landDataMan, v0, v1, v2);
         LandDataManager_SetInDistortionWorld(fieldSystem->landDataMan, TRUE);
         LandDataManager_SetSkipMapProps(fieldSystem->landDataMan, TRUE);
diff --git a/src/overlay005/honey_tree.c b/src/overlay005/honey_tree.c
index f8625a6cfd..f0d9815f73 100644
--- a/src/overlay005/honey_tree.c
+++ b/src/overlay005/honey_tree.c
@@ -31,14 +31,14 @@
 static void GetTreeEncounterGroup(const BOOL isMunchlaxTree, u8 *param1);
 static void GetTreeEncounterSlot(u8 *slot);
 static void DoTreeShakingAnimation(FieldSystem *fieldSystem, MapPropManager *param1, const int param2);
-static u8 GetTreeIdFromMapId(const int param0);
+static u8 GetTreeIDFromMapHeaderID(const enum MapHeaderID mapHeaderID);
 static const int GetEncounterTableFromGroup(const u8 param0);
 static const int GetShakesFromGroup(const u8 param0);
 static const BOOL GetShakingValue(const int numShakes, u8 *value);
 static const BOOL SixHoursSinceSlathered(const int param0);
 static BOOL IsMunchlaxTree(const u32 param0, const u8 param1);
 
-static const int sHoneyTreeMapIds[NUM_HONEY_TREES] = {
+static const int sHoneyTreeMapHeaderIDs[NUM_HONEY_TREES] = {
     MAP_HEADER_ROUTE_205_SOUTH,
     MAP_HEADER_ROUTE_205_NORTH,
     MAP_HEADER_ROUTE_206,
@@ -117,15 +117,11 @@ BOOL HoneyTree_TryInteract(FieldSystem *fieldSystem, int *eventId)
 
 u16 HoneyTree_GetTreeSlatherStatus(FieldSystem *fieldSystem)
 {
-    u8 treeId;
-    PlayerHoneyTreeStates *treeDat;
-    HoneyTree *tree;
-
-    treeId = GetTreeIdFromMapId(fieldSystem->location->mapId);
+    u8 treeId = GetTreeIDFromMapHeaderID(fieldSystem->location->mapHeaderID);
     GF_ASSERT(treeId != NUM_HONEY_TREES);
 
-    treeDat = SpecialEncounter_GetPlayerHoneyTreeStates(SaveData_GetSpecialEncounters(fieldSystem->saveData));
-    tree = SpecialEncounter_GetHoneyTree(treeId, treeDat);
+    PlayerHoneyTreeStates *treeDat = SpecialEncounter_GetPlayerHoneyTreeStates(SaveData_GetSpecialEncounters(fieldSystem->saveData));
+    HoneyTree *tree = SpecialEncounter_GetHoneyTree(treeId, treeDat);
 
     if (SixHoursSinceSlathered(tree->minutesRemaining)) {
         return TREE_STATUS_ENCOUNTER; // tree can have Pokemon
@@ -138,21 +134,16 @@ u16 HoneyTree_GetTreeSlatherStatus(FieldSystem *fieldSystem)
 
 void HoneyTree_SlatherTree(FieldSystem *fieldSystem)
 {
-    u8 treeId;
-    PlayerHoneyTreeStates *treeDat;
-    HoneyTree *tree;
-    BOOL munchlaxTree;
-
-    treeId = GetTreeIdFromMapId(fieldSystem->location->mapId);
+    u8 treeId = GetTreeIDFromMapHeaderID(fieldSystem->location->mapHeaderID);
     GF_ASSERT(treeId != NUM_HONEY_TREES);
 
-    treeDat = SpecialEncounter_GetPlayerHoneyTreeStates(SaveData_GetSpecialEncounters(fieldSystem->saveData));
-    tree = SpecialEncounter_GetHoneyTree(treeId, treeDat);
+    PlayerHoneyTreeStates *treeDat = SpecialEncounter_GetPlayerHoneyTreeStates(SaveData_GetSpecialEncounters(fieldSystem->saveData));
+    HoneyTree *tree = SpecialEncounter_GetHoneyTree(treeId, treeDat);
 
     tree->minutesRemaining = (24 * 60); // slathering lasts for one day
 
     TrainerInfo *trainer = SaveData_GetTrainerInfo(fieldSystem->saveData);
-    munchlaxTree = IsMunchlaxTree(TrainerInfo_ID(trainer), treeId);
+    BOOL munchlaxTree = IsMunchlaxTree(TrainerInfo_ID(trainer), treeId);
 
     // Slathering the same tree twice in succession has a 90% chance to give the same group again.
     if (SpecialEncounter_GetLastSlatheredTreeId(treeDat) == treeId) {
@@ -182,21 +173,18 @@ void HoneyTree_SlatherTree(FieldSystem *fieldSystem)
 
 void HoneyTree_StopShaking(FieldSystem *fieldSystem)
 {
-    u8 treeId = GetTreeIdFromMapId(fieldSystem->location->mapId);
+    u8 treeId = GetTreeIDFromMapHeaderID(fieldSystem->location->mapHeaderID);
     GF_ASSERT(treeId != NUM_HONEY_TREES);
 
     if (fieldSystem->unk_A8->trees[treeId].isShaking) {
-        u8 v1;
-        MapProp *v2;
         MapPropManager *v3;
-        NNSG3dRenderObj *v4;
 
-        v1 = LandDataManager_GetTrackedTargetLoadedMapsQuadrant(fieldSystem->landDataMan);
+        u8 v1 = LandDataManager_GetTrackedTargetLoadedMapsQuadrant(fieldSystem->landDataMan);
 
         LandDataManager_GetLoadedMapPropManager(v1, fieldSystem->landDataMan, &v3);
 
-        v2 = MapPropManager_FindLoadedPropByModelID(v3, honey_tree_nsbmd);
-        v4 = MapProp_GetRenderObj(v2);
+        MapProp *v2 = MapPropManager_FindLoadedPropByModelID(v3, honey_tree_nsbmd);
+        NNSG3dRenderObj *v4 = MapProp_GetRenderObj(v2);
 
         if (v2 != NULL) {
             MapPropAnimationManager_RemoveAnimationFromRenderObj(fieldSystem->mapPropAnimMan, v4, honey_tree_nsbmd, fieldSystem->unk_A8->trees[treeId].shakeValue);
@@ -341,36 +329,24 @@ static const BOOL GetShakingValue(const int numShakes, u8 *value)
 
 static void DoTreeShakingAnimation(FieldSystem *fieldSystem, MapPropManager *param1, const int param2)
 {
-    u16 mapId;
-    u8 treeId;
-
-    mapId = MapMatrix_GetMapHeaderIDAtIndex(fieldSystem->mapMatrix, param2);
-    treeId = GetTreeIdFromMapId(mapId);
+    u16 mapId = MapMatrix_GetMapHeaderIDAtIndex(fieldSystem->mapMatrix, param2);
+    u8 treeId = GetTreeIDFromMapHeaderID(mapId);
 
     if (treeId != NUM_HONEY_TREES) {
-        PlayerHoneyTreeStates *treeDat;
-        HoneyTree *tree;
-        MapProp *v4;
-
-        treeDat = SpecialEncounter_GetPlayerHoneyTreeStates(SaveData_GetSpecialEncounters(fieldSystem->saveData));
-        tree = SpecialEncounter_GetHoneyTree(treeId, treeDat);
+        PlayerHoneyTreeStates *treeDat = SpecialEncounter_GetPlayerHoneyTreeStates(SaveData_GetSpecialEncounters(fieldSystem->saveData));
+        HoneyTree *tree = SpecialEncounter_GetHoneyTree(treeId, treeDat);
 
         if (SixHoursSinceSlathered(tree->minutesRemaining)) {
-            BOOL isShaking;
             u8 shakeValue;
-
-            isShaking = GetShakingValue(tree->numShakes, &shakeValue);
-
+            BOOL isShaking = GetShakingValue(tree->numShakes, &shakeValue);
             if (!isShaking) {
                 return;
             }
 
-            v4 = MapPropManager_FindLoadedPropByModelID(param1, honey_tree_nsbmd);
+            MapProp *v4 = MapPropManager_FindLoadedPropByModelID(param1, honey_tree_nsbmd);
 
             if (v4 != NULL) {
-                NNSG3dRenderObj *v7;
-
-                v7 = MapProp_GetRenderObj(v4);
+                NNSG3dRenderObj *v7 = MapProp_GetRenderObj(v4);
 
                 MapPropAnimationManager_RemoveAnimationFromRenderObj(fieldSystem->mapPropAnimMan, v7, honey_tree_nsbmd, fieldSystem->unk_A8->trees[treeId].shakeValue);
 
@@ -384,11 +360,11 @@ static void DoTreeShakingAnimation(FieldSystem *fieldSystem, MapPropManager *par
 }
 
 // Returns NUM_HONEY_TREES if map does not have a Honey Tree.
-static u8 GetTreeIdFromMapId(const int mapId)
+static u8 GetTreeIDFromMapHeaderID(const enum MapHeaderID mapHeaderID)
 {
     u8 i;
     for (i = 0; i < NUM_HONEY_TREES; i++) {
-        if (mapId == sHoneyTreeMapIds[i]) {
+        if (mapHeaderID == sHoneyTreeMapHeaderIDs[i]) {
             return i;
         }
     }
@@ -444,11 +420,10 @@ static BOOL IsMunchlaxTree(const u32 trainerId, const u8 treeId)
 
 int HoneyTree_GetSpecies(FieldSystem *fieldSystem)
 {
-    u8 treeId = GetTreeIdFromMapId(fieldSystem->location->mapId);
+    u8 treeId = GetTreeIDFromMapHeaderID(fieldSystem->location->mapHeaderID);
     GF_ASSERT(treeId != NUM_HONEY_TREES);
 
     int *narcData;
-    int species;
     PlayerHoneyTreeStates *treeDat = SpecialEncounter_GetPlayerHoneyTreeStates(SaveData_GetSpecialEncounters(fieldSystem->saveData));
     HoneyTree *tree = SpecialEncounter_GetHoneyTree(treeId, treeDat);
 
@@ -458,7 +433,7 @@ int HoneyTree_GetSpecies(FieldSystem *fieldSystem)
         narcData = NARC_AllocAtEndAndReadWholeMemberByIndexPair(NARC_INDEX_ARC__ENCDATA_EX, sEncounterTableIndexes_P_Unused[tree->encounterTableIndex], HEAP_ID_FIELD1);
     }
 
-    species = narcData[tree->encounterSlot];
+    int species = narcData[tree->encounterSlot];
     Heap_Free(narcData);
 
     return species;
@@ -466,27 +441,23 @@ int HoneyTree_GetSpecies(FieldSystem *fieldSystem)
 
 void ov5_021F0030(void *param0, const int param1, MapPropManager *const mapPropManager)
 {
-    FieldSystem *fieldSystem;
-
     if (param1 < 0) {
         return;
     }
 
-    fieldSystem = (FieldSystem *)param0;
+    FieldSystem *fieldSystem = (FieldSystem *)param0;
     DoTreeShakingAnimation(fieldSystem, mapPropManager, param1);
 }
 
 void HoneyTree_Unslather(FieldSystem *fieldSystem)
 {
-    PlayerHoneyTreeStates *treeDat;
-    HoneyTree *tree;
-    u8 treeId = GetTreeIdFromMapId(fieldSystem->location->mapId);
+    u8 treeId = GetTreeIDFromMapHeaderID(fieldSystem->location->mapHeaderID);
     GF_ASSERT(treeId != NUM_HONEY_TREES);
 
     fieldSystem->unk_A8->trees[treeId].isShaking = FALSE;
 
-    treeDat = SpecialEncounter_GetPlayerHoneyTreeStates(SaveData_GetSpecialEncounters(fieldSystem->saveData));
-    tree = SpecialEncounter_GetHoneyTree(treeId, treeDat);
+    PlayerHoneyTreeStates *treeDat = SpecialEncounter_GetPlayerHoneyTreeStates(SaveData_GetSpecialEncounters(fieldSystem->saveData));
+    HoneyTree *tree = SpecialEncounter_GetHoneyTree(treeId, treeDat);
 
     tree->minutesRemaining = 0;
 }
diff --git a/src/overlay005/map_name_popup.c b/src/overlay005/map_name_popup.c
index a32d6edb82..079404c29d 100644
--- a/src/overlay005/map_name_popup.c
+++ b/src/overlay005/map_name_popup.c
@@ -267,13 +267,13 @@ void MapNamePopUp_Hide(MapNamePopUp *mapPopUp)
 
 void FieldSystem_RequestLocationName(FieldSystem *fieldSystem)
 {
-    if (MapHeader_GetMapLabelWindowID(fieldSystem->location->mapId) == 0) {
+    if (MapHeader_GetMapLabelWindowID(fieldSystem->location->mapHeaderID) == 0) {
         return;
     }
 
-    if (!MapHeader_IsBuilding(fieldSystem->location->mapId)) {
-        u32 mapLabelTextID = MapHeader_GetMapLabelTextID(fieldSystem->location->mapId);
-        u32 mapLabelWindowID = MapHeader_GetMapLabelWindowID(fieldSystem->location->mapId);
+    if (!MapHeader_IsBuilding(fieldSystem->location->mapHeaderID)) {
+        u32 mapLabelTextID = MapHeader_GetMapLabelTextID(fieldSystem->location->mapHeaderID);
+        u32 mapLabelWindowID = MapHeader_GetMapLabelWindowID(fieldSystem->location->mapHeaderID);
 
         if (mapLabelWindowID != 0) {
             mapLabelWindowID--;
diff --git a/src/overlay005/ov5_021DFB54.c b/src/overlay005/ov5_021DFB54.c
index 61334c1a9d..40f1c0def9 100644
--- a/src/overlay005/ov5_021DFB54.c
+++ b/src/overlay005/ov5_021DFB54.c
@@ -832,7 +832,7 @@ static BOOL ov5_021E03C8(FieldTask *param0)
 
         PlayerAvatar_SetSurfMountAnimManager(v0->playerAvatar, NULL);
         PlayerAvatar_SetPlayerState(v0->playerAvatar, 0x0);
-        FieldBGM_TryFadeOut(v0->fieldSystem, FieldBGM_GetForMapHeader(v0->fieldSystem, v0->fieldSystem->location->mapId), 1);
+        FieldBGM_TryFadeOut(v0->fieldSystem, FieldBGM_GetForMapHeader(v0->fieldSystem, v0->fieldSystem->location->mapHeaderID), 1);
         MonRideTaskEnv_Free(v0);
         return 1;
     }
diff --git a/src/overlay005/ov5_021F007C.c b/src/overlay005/ov5_021F007C.c
index e98e591572..2f9fb26206 100644
--- a/src/overlay005/ov5_021F007C.c
+++ b/src/overlay005/ov5_021F007C.c
@@ -467,7 +467,7 @@ BOOL ov5_021F0488(FieldTask *param0)
     case 3:
         v1->unk_0E--;
 
-        if (MapHeader_HasWildEncounters(fieldSystem->location->mapId)) {
+        if (MapHeader_HasWildEncounters(fieldSystem->location->mapHeaderID)) {
             if (v1->unk_0E < 0) {
                 {
                     u8 v3;
diff --git a/src/overlay005/ov5_021F10E8.c b/src/overlay005/ov5_021F10E8.c
index db14ea25ae..c1a990aee4 100644
--- a/src/overlay005/ov5_021F10E8.c
+++ b/src/overlay005/ov5_021F10E8.c
@@ -206,7 +206,7 @@ static int ov5_021F1258(OverworldAnimManager *param0, void *param1)
     if (sub_02062E94(v0->unk_1C.unk_08) == 1) {
         v0->unk_08 = sub_02062C18(v0->unk_1C.unk_08);
     } else {
-        v0->unk_08 = MapObject_GetMapID(v0->unk_1C.unk_08);
+        v0->unk_08 = MapObject_GetMapHeaderID(v0->unk_1C.unk_08);
     }
 
     OverworldAnimManager_GetPosition(param0, &v0->unk_0C);
diff --git a/src/overlay005/ov5_021F134C.c b/src/overlay005/ov5_021F134C.c
index e1b28bca9a..50ee204de0 100644
--- a/src/overlay005/ov5_021F134C.c
+++ b/src/overlay005/ov5_021F134C.c
@@ -227,7 +227,7 @@ static int ov5_021F15B4(OverworldAnimManager *param0, void *param1)
     if (sub_02062E94(v0->unk_14.unk_08) == 1) {
         v0->unk_08 = sub_02062C18(v0->unk_14.unk_08);
     } else {
-        v0->unk_08 = MapObject_GetMapID(v0->unk_14.unk_08);
+        v0->unk_08 = MapObject_GetMapHeaderID(v0->unk_14.unk_08);
     }
 
     return 1;
diff --git a/src/overlay005/ov5_021F17B8.c b/src/overlay005/ov5_021F17B8.c
index 801d6d6610..54888cd547 100644
--- a/src/overlay005/ov5_021F17B8.c
+++ b/src/overlay005/ov5_021F17B8.c
@@ -121,7 +121,7 @@ static int ov5_021F184C(OverworldAnimManager *param0, void *param1)
     v1->unk_14 = *v2;
     v1->unk_10 = OverworldAnimManager_GetUserInt(param0);
     v1->unk_00 = MapObject_GetLocalID(v1->unk_14.unk_0C);
-    v1->unk_04 = MapObject_GetMapID(v1->unk_14.unk_0C);
+    v1->unk_04 = MapObject_GetMapHeaderID(v1->unk_14.unk_0C);
     v1->unk_08 = MapObject_GetGraphicsID(v1->unk_14.unk_0C);
 
     if (BerryPatchGraphics_IsBerryPatch(v1->unk_08) == 1) {
diff --git a/src/overlay005/ov5_021F23D0.c b/src/overlay005/ov5_021F23D0.c
index 0426010f14..42ecc8cbd4 100644
--- a/src/overlay005/ov5_021F23D0.c
+++ b/src/overlay005/ov5_021F23D0.c
@@ -112,7 +112,7 @@ static int ov5_021F2488(OverworldAnimManager *param0, void *param1)
     Simple3D_CreateRenderObjectWithAnim(&v0->unk_40, &v0->unk_10.unk_04->unk_04, &v0->unk_1C);
 
     v0->unk_04 = MapObject_GetLocalID(v0->unk_10.unk_08);
-    v0->unk_08 = MapObject_GetMapID(v0->unk_10.unk_08);
+    v0->unk_08 = MapObject_GetMapHeaderID(v0->unk_10.unk_08);
 
     {
         VecFx32 v2, v3;
diff --git a/src/overlay005/ov5_021F2D20.c b/src/overlay005/ov5_021F2D20.c
index ab61e3b989..2c159433ed 100644
--- a/src/overlay005/ov5_021F2D20.c
+++ b/src/overlay005/ov5_021F2D20.c
@@ -178,7 +178,7 @@ static int ov5_021F2F0C(OverworldAnimManager *param0, void *param1)
     v3->unk_18 = *v4;
     v3->unk_04 = MapObject_GetEffectiveGraphicsID(v3->unk_18.unk_18);
     v3->unk_08 = MapObject_GetLocalID(v3->unk_18.unk_18);
-    v3->unk_0C = MapObject_GetMapID(v3->unk_18.unk_18);
+    v3->unk_0C = MapObject_GetMapHeaderID(v3->unk_18.unk_18);
 
     v2.x = (((v3->unk_18.unk_00) << 4) * FX32_ONE);
     v2.z = (((v3->unk_18.unk_08) << 4) * FX32_ONE);
diff --git a/src/overlay005/ov5_021F3284.c b/src/overlay005/ov5_021F3284.c
index ef030c491a..8fb520ab41 100644
--- a/src/overlay005/ov5_021F3284.c
+++ b/src/overlay005/ov5_021F3284.c
@@ -105,7 +105,7 @@ static int ov5_021F336C(OverworldAnimManager *param0, void *param1)
     v1->unk_14 = *v2;
     v1->unk_04 = MapObject_GetEffectiveGraphicsID(v1->unk_14.unk_0C);
     v1->unk_08 = MapObject_GetLocalID(v1->unk_14.unk_0C);
-    v1->unk_0C = MapObject_GetMapID(v1->unk_14.unk_0C);
+    v1->unk_0C = MapObject_GetMapHeaderID(v1->unk_14.unk_0C);
 
     OverworldAnimManager_SetPosition(param0, &v0);
     v1->unk_24 = ov5_021DF84C(v1->unk_14.unk_04, 3, &v0);
diff --git a/src/overlay005/ov5_021F348C.c b/src/overlay005/ov5_021F348C.c
index 8b5aec9085..c7a656e3b8 100644
--- a/src/overlay005/ov5_021F348C.c
+++ b/src/overlay005/ov5_021F348C.c
@@ -185,7 +185,7 @@ static int ov5_021F36F4(OverworldAnimManager *param0, void *param1)
 
     v2->unk_10 = *v3;
     v2->unk_04 = MapObject_GetLocalID(v2->unk_10.unk_0C);
-    v2->unk_08 = MapObject_GetMapID(v2->unk_10.unk_0C);
+    v2->unk_08 = MapObject_GetMapHeaderID(v2->unk_10.unk_0C);
 
     OverworldAnimManager_GetPosition(param0, &v1);
 
diff --git a/src/overlay005/ov5_021F37A8.c b/src/overlay005/ov5_021F37A8.c
index b9a3d7788a..70e0f349f2 100644
--- a/src/overlay005/ov5_021F37A8.c
+++ b/src/overlay005/ov5_021F37A8.c
@@ -114,7 +114,7 @@ static int ov5_021F38AC(OverworldAnimManager *param0, void *param1)
     v3->unk_18 = *v4;
     v3->unk_04 = MapObject_GetEffectiveGraphicsID(v3->unk_18.unk_18);
     v3->unk_08 = MapObject_GetLocalID(v3->unk_18.unk_18);
-    v3->unk_0C = MapObject_GetMapID(v3->unk_18.unk_18);
+    v3->unk_0C = MapObject_GetMapHeaderID(v3->unk_18.unk_18);
 
     v2.x = (((v3->unk_18.unk_00) << 4) * FX32_ONE);
     v2.z = (((v3->unk_18.unk_08) << 4) * FX32_ONE);
diff --git a/src/overlay005/ov5_021F3A50.c b/src/overlay005/ov5_021F3A50.c
index b4c2b64013..ef3a3814d8 100644
--- a/src/overlay005/ov5_021F3A50.c
+++ b/src/overlay005/ov5_021F3A50.c
@@ -114,7 +114,7 @@ static int ov5_021F3B54(OverworldAnimManager *param0, void *param1)
     v3->unk_18 = *v4;
     v3->unk_04 = MapObject_GetEffectiveGraphicsID(v3->unk_18.unk_18);
     v3->unk_08 = MapObject_GetLocalID(v3->unk_18.unk_18);
-    v3->unk_0C = MapObject_GetMapID(v3->unk_18.unk_18);
+    v3->unk_0C = MapObject_GetMapHeaderID(v3->unk_18.unk_18);
 
     v2.x = (((v3->unk_18.unk_00) << 4) * FX32_ONE);
     v2.z = (((v3->unk_18.unk_08) << 4) * FX32_ONE);
diff --git a/src/overlay005/ov5_021F3D00.c b/src/overlay005/ov5_021F3D00.c
index fb984b540d..8595e2b582 100644
--- a/src/overlay005/ov5_021F3D00.c
+++ b/src/overlay005/ov5_021F3D00.c
@@ -124,7 +124,7 @@ static int ov5_021F3E00(OverworldAnimManager *param0, void *param1)
 
     v0->unk_10 = *v1;
     v0->unk_08 = MapObject_GetLocalID(v2);
-    v0->unk_0C = MapObject_GetMapID(v2);
+    v0->unk_0C = MapObject_GetMapHeaderID(v2);
 
     return 1;
 }
diff --git a/src/overlay005/ov5_021F3E74.c b/src/overlay005/ov5_021F3E74.c
index a0b0d10dd0..3f861cc2c1 100644
--- a/src/overlay005/ov5_021F3E74.c
+++ b/src/overlay005/ov5_021F3E74.c
@@ -106,7 +106,7 @@ static int ov5_021F3F74(OverworldAnimManager *param0, void *param1)
 
     v1->unk_10 = *v2;
     v1->unk_04 = MapObject_GetLocalID(v1->unk_10.unk_0C);
-    v1->unk_08 = MapObject_GetMapID(v1->unk_10.unk_0C);
+    v1->unk_08 = MapObject_GetMapHeaderID(v1->unk_10.unk_0C);
 
     OverworldAnimManager_GetPosition(param0, &v0);
 
diff --git a/src/overlay005/ov5_021F50BC.c b/src/overlay005/ov5_021F50BC.c
index bdda9bc1a6..392a4af784 100644
--- a/src/overlay005/ov5_021F50BC.c
+++ b/src/overlay005/ov5_021F50BC.c
@@ -31,7 +31,7 @@ typedef struct {
     int unk_00;
     int unk_04;
     int unk_08;
-    int unk_0C;
+    enum MapHeaderID unk_0C;
     int unk_10;
     int unk_14;
     VecFx32 unk_18;
@@ -96,16 +96,14 @@ OverworldAnimManager *ov5_021F511C(MapObject *param0)
 
 static int ov5_021F5158(OverworldAnimManager *param0, void *param1)
 {
-    UnkStruct_ov5_021F5158 *v0;
-    const UnkStruct_ov5_021F511C *v1;
     VecFx32 v2;
 
-    v0 = param1;
-    v1 = OverworldAnimManager_GetUserData(param0);
+    UnkStruct_ov5_021F5158 *v0 = param1;
+    const UnkStruct_ov5_021F511C *v1 = OverworldAnimManager_GetUserData(param0);
 
     v0->unk_30 = *v1;
     v0->unk_08 = MapObject_GetLocalID(v0->unk_30.unk_08);
-    v0->unk_0C = MapObject_GetMapID(v0->unk_30.unk_08);
+    v0->unk_0C = MapObject_GetMapHeaderID(v0->unk_30.unk_08);
     v0->unk_24.y = (FX32_ONE * 6);
 
     MapObject_GetPosPtr(v0->unk_30.unk_08, &v2);
diff --git a/src/overlay005/ov5_021F5284.c b/src/overlay005/ov5_021F5284.c
index 7a13f8f8a4..d89dd17625 100644
--- a/src/overlay005/ov5_021F5284.c
+++ b/src/overlay005/ov5_021F5284.c
@@ -107,7 +107,7 @@ static int ov5_021F5320(OverworldAnimManager *param0, void *param1)
 
     v0->unk_30 = *v1;
     v0->unk_08 = MapObject_GetLocalID(v0->unk_30.unk_08);
-    v0->unk_0C = MapObject_GetMapID(v0->unk_30.unk_08);
+    v0->unk_0C = MapObject_GetMapHeaderID(v0->unk_30.unk_08);
     v0->unk_24.y = (FX32_ONE * 6);
 
     MapObject_GetPosPtr(v0->unk_30.unk_08, &v2);
diff --git a/src/overlay005/ov5_021F5428.c b/src/overlay005/ov5_021F5428.c
index 2e65b43b0b..0d6d82af6f 100644
--- a/src/overlay005/ov5_021F5428.c
+++ b/src/overlay005/ov5_021F5428.c
@@ -107,7 +107,7 @@ static int ov5_021F54C4(OverworldAnimManager *param0, void *param1)
 
     v0->unk_34 = *v1;
     v0->unk_08 = MapObject_GetLocalID(v0->unk_34.unk_08);
-    v0->unk_0C = MapObject_GetMapID(v0->unk_34.unk_08);
+    v0->unk_0C = MapObject_GetMapHeaderID(v0->unk_34.unk_08);
     v0->unk_24.y = (FX32_ONE * 6);
 
     MapObject_GetPosPtr(v0->unk_34.unk_08, &v2);
diff --git a/src/overlay005/ov5_021F5A10.c b/src/overlay005/ov5_021F5A10.c
index 9332c49008..ff682a65f7 100644
--- a/src/overlay005/ov5_021F5A10.c
+++ b/src/overlay005/ov5_021F5A10.c
@@ -381,7 +381,7 @@ static int ov5_021F5DE4(OverworldAnimManager *param0, void *param1)
 
     v1->unk_30 = *v2;
     v1->unk_08 = MapObject_GetLocalID(v1->unk_30.unk_0C);
-    v1->unk_0C = MapObject_GetMapID(v1->unk_30.unk_0C);
+    v1->unk_0C = MapObject_GetMapHeaderID(v1->unk_30.unk_0C);
     v1->unk_24.y = (FX32_ONE * 6);
 
     ov5_021F5BF0(v1->unk_30.unk_08, v1->unk_30.unk_00);
@@ -450,7 +450,7 @@ static int ov5_021F5EE0(OverworldAnimManager *param0, void *param1)
 
     v1->unk_30 = *v2;
     v1->unk_08 = MapObject_GetLocalID(v1->unk_30.unk_0C);
-    v1->unk_0C = MapObject_GetMapID(v1->unk_30.unk_0C);
+    v1->unk_0C = MapObject_GetMapHeaderID(v1->unk_30.unk_0C);
     v1->unk_24.y = (FX32_ONE * 6);
     v1->unk_10 = 1;
 
diff --git a/src/overlay005/ov5_021F600C.c b/src/overlay005/ov5_021F600C.c
index e21d98cc85..9e7281c687 100644
--- a/src/overlay005/ov5_021F600C.c
+++ b/src/overlay005/ov5_021F600C.c
@@ -103,7 +103,7 @@ static int ov5_021F60E4(OverworldAnimManager *param0, void *param1)
 
     v1->unk_10 = *v2;
     v1->unk_04 = MapObject_GetLocalID(v1->unk_10.unk_0C);
-    v1->unk_08 = MapObject_GetMapID(v1->unk_10.unk_0C);
+    v1->unk_08 = MapObject_GetMapHeaderID(v1->unk_10.unk_0C);
 
     OverworldAnimManager_SetPosition(param0, &v0);
     v1->unk_20 = ov5_021DF84C(v1->unk_10.unk_04, 4, &v0);
diff --git a/src/overlay005/ov5_021F61BC.c b/src/overlay005/ov5_021F61BC.c
index 900256fa42..364ac88db1 100644
--- a/src/overlay005/ov5_021F61BC.c
+++ b/src/overlay005/ov5_021F61BC.c
@@ -108,7 +108,7 @@ static int ov5_021F6264(OverworldAnimManager *param0, void *param1)
 
     v0->unk_04 = -1;
     v0->unk_14 = MapObject_GetLocalID(v1);
-    v0->unk_18 = MapObject_GetMapID(v1);
+    v0->unk_18 = MapObject_GetMapHeaderID(v1);
 
     return 1;
 }
diff --git a/src/overlay005/save_info_window.c b/src/overlay005/save_info_window.c
index 652c8bda45..ef0ed63613 100644
--- a/src/overlay005/save_info_window.c
+++ b/src/overlay005/save_info_window.c
@@ -50,7 +50,7 @@ static void SaveInfo_SetValues(SaveInfo *saveInfo, const FieldSystem *fieldSyste
     Location *curLocation = FieldOverworldState_GetPlayerLocation(SaveData_GetFieldOverworldState(saveData));
     Pokedex *pokedex = SaveData_GetPokedex(saveData);
 
-    saveInfo->mapLabelTextID = MapHeader_GetMapLabelTextID(curLocation->mapId);
+    saveInfo->mapLabelTextID = MapHeader_GetMapLabelTextID(curLocation->mapHeaderID);
 
     if (Pokedex_IsObtained(pokedex)) {
         saveInfo->pokedexCount = Pokedex_CountSeen(pokedex);
@@ -209,7 +209,7 @@ void FieldSystem_SaveStateIfCommunicationOff(FieldSystem *fieldSystem)
         return;
     }
 
-    switch (fieldSystem->location->mapId) {
+    switch (fieldSystem->location->mapHeaderID) {
     case MAP_HEADER_UNION_ROOM:
     case MAP_HEADER_COMMUNICATION_CLUB_COLOSSEUM_2P:
     case MAP_HEADER_COMMUNICATION_CLUB_COLOSSEUM_4P:
diff --git a/src/overlay005/surf_mount_renderer.c b/src/overlay005/surf_mount_renderer.c
index ea36f001d2..3d6fb87881 100644
--- a/src/overlay005/surf_mount_renderer.c
+++ b/src/overlay005/surf_mount_renderer.c
@@ -120,7 +120,7 @@ static BOOL SurfMountRenderer_AnimInit(OverworldAnimManager *animMan, void *cont
 
     renderer->userData = *userData;
     renderer->mapObjLocalID = MapObject_GetLocalID(playerMapObj);
-    renderer->mapHeaderID = MapObject_GetMapID(playerMapObj);
+    renderer->mapHeaderID = MapObject_GetMapHeaderID(playerMapObj);
     renderer->dir = userData->dir;
     renderer->syncPos = OverworldAnimManager_GetUserInt(animMan);
     renderer->yOffset = RENDERER_INITIAL_Y_OFFSET;
diff --git a/src/overlay006/field_warp.c b/src/overlay006/field_warp.c
index 86c45c5d02..a6e1c3af68 100644
--- a/src/overlay006/field_warp.c
+++ b/src/overlay006/field_warp.c
@@ -280,7 +280,7 @@ static void CreateJournalEntryForTeleport(FieldSystem *fieldSystem, FieldWarp *f
         return;
     }
 
-    void *journalEntryLocationEvent = JournalEntry_CreateEventUsedMove(FIELD_MOVE_TELEPORT, fieldSystem->location->mapId, HEAP_ID_FIELD1);
+    void *journalEntryLocationEvent = JournalEntry_CreateEventUsedMove(FIELD_MOVE_TELEPORT, fieldSystem->location->mapHeaderID, HEAP_ID_FIELD1);
     JournalEntry_SaveData(fieldSystem->journalEntry, journalEntryLocationEvent, JOURNAL_LOCATION);
 }
 
diff --git a/src/overlay006/great_marsh_binoculars.c b/src/overlay006/great_marsh_binoculars.c
index a0e01cce36..7fd81ef86e 100644
--- a/src/overlay006/great_marsh_binoculars.c
+++ b/src/overlay006/great_marsh_binoculars.c
@@ -3,6 +3,8 @@
 #include <nitro.h>
 #include <string.h>
 
+#include "generated/map_headers.h"
+
 #include "field/field_system.h"
 #include "overlay006/dual_slot_encounters.h"
 #include "overlay006/great_marsh_daily_encounters.h"
@@ -32,7 +34,7 @@ int GreatMarshBinoculars_GetMonSpecies(FieldSystem *fieldSystem)
 
     BOOL natDexObtained = Pokedex_IsNationalDexObtained(SaveData_GetPokedex(FieldSystem_GetSaveData(fieldSystem)));
 
-    ReplaceGreatMarshDailyEncounters(SpecialEncounter_GetDailyMon(SaveData_GetSpecialEncounters(fieldSystem->saveData), DAILY_MARSH), natDexObtained, fieldSystem->location->mapId, &encounterTable[6], &encounterTable[7]);
+    ReplaceGreatMarshDailyEncounters(SpecialEncounter_GetDailyMon(SaveData_GetSpecialEncounters(fieldSystem->saveData), DAILY_MARSH), natDexObtained, fieldSystem->location->mapHeaderID, &encounterTable[6], &encounterTable[7]);
     WildEncounters_ReplaceTimedEncounters(encounterData, &encounterTable[2], &encounterTable[3]);
     WildEncounters_ReplaceDualSlotEncounters(encounterData, natDexObtained, &encounterTable[8], &encounterTable[9]);
 
@@ -56,7 +58,7 @@ GreatMarshBinoculars *GreatMarshBinoculars_InitData(const enum HeapID heapID, Fi
 
     binocularsData->coordsList[BINOCULARS_CYCLE_COUNT].x = PlayerAvatar_GetXPos(fieldSystem->playerAvatar);
     binocularsData->coordsList[BINOCULARS_CYCLE_COUNT].z = PlayerAvatar_GetZPos(fieldSystem->playerAvatar);
-    binocularsData->lookoutMapId = fieldSystem->location->mapId;
+    binocularsData->lookoutMapHeaderID = fieldSystem->location->mapHeaderID;
     Heap_Free(coordData);
 
     return binocularsData;
@@ -69,23 +71,23 @@ void GreatMarshBinoculars_FreeData(GreatMarshBinoculars *data)
 
 void GreatMarshBinoculars_SetNextLocationWithCoords(const u8 cycleNum, GreatMarshBinoculars *binocularsData)
 {
-    int nextMapId;
+    enum MapHeaderID nextMapHeaderID;
     int nextX, nextZ;
 
     if (cycleNum == 0) {
         int v3 = 240; // member number for NARC_INDEX_FIELDDATA__MAPMATRIX__MAP_MATRIX. Not sure what it represents exactly.
         nextX = binocularsData->coordsList[cycleNum].x / 32;
         nextZ = binocularsData->coordsList[cycleNum].z / 32;
-        nextMapId = MapMatrixData_GetMapHeaderIDAtCoords(v3, nextX, nextZ);
+        nextMapHeaderID = MapMatrixData_GetMapHeaderIDAtCoords(v3, nextX, nextZ);
     } else if (cycleNum == BINOCULARS_CYCLE_COUNT) {
-        nextMapId = binocularsData->lookoutMapId;
+        nextMapHeaderID = binocularsData->lookoutMapHeaderID;
     } else {
         nextX = binocularsData->coordsList[cycleNum].x / 32;
         nextZ = binocularsData->coordsList[cycleNum].z / 32;
-        nextMapId = MapMatrix_GetMapHeaderIDAtCoords(binocularsData->fieldSystem->mapMatrix, nextX, nextZ);
+        nextMapHeaderID = MapMatrix_GetMapHeaderIDAtCoords(binocularsData->fieldSystem->mapMatrix, nextX, nextZ);
     }
 
-    Location_Set(&binocularsData->viewLocation, nextMapId, -1, binocularsData->coordsList[cycleNum].x, binocularsData->coordsList[cycleNum].z, 0);
+    Location_Set(&binocularsData->viewLocation, nextMapHeaderID, -1, binocularsData->coordsList[cycleNum].x, binocularsData->coordsList[cycleNum].z, 0);
 }
 
 Location *GreatMarshBinoculars_GetLocation(GreatMarshBinoculars *binocData)
diff --git a/src/overlay006/great_marsh_daily_encounters.c b/src/overlay006/great_marsh_daily_encounters.c
index 68f4e4a95e..74c58cabf0 100644
--- a/src/overlay006/great_marsh_daily_encounters.c
+++ b/src/overlay006/great_marsh_daily_encounters.c
@@ -6,14 +6,12 @@
 #include "heap.h"
 #include "narc.h"
 
-static u8 GreatMarsh_GetAreaNumFromMapId(const int mapId);
+static u8 GreatMarsh_GetAreaNumFromMapId(const enum MapHeaderID mapHeaderID);
 
-void ReplaceGreatMarshDailyEncounters(const int dailyMon, const BOOL nationalDexObtained, const int mapId, int *encounterSlot1, int *encounterSlot2)
+void ReplaceGreatMarshDailyEncounters(const int dailyMon, const BOOL nationalDexObtained, const enum MapHeaderID mapHeaderID, int *encounterSlot1, int *encounterSlot2)
 {
-    int *narc;
     int encDataGroup;
-    u8 encounterIndex;
-    u8 areaNum = GreatMarsh_GetAreaNumFromMapId(mapId);
+    u8 areaNum = GreatMarsh_GetAreaNumFromMapId(mapHeaderID);
 
     if (nationalDexObtained) {
         encDataGroup = 9;
@@ -21,8 +19,8 @@ void ReplaceGreatMarshDailyEncounters(const int dailyMon, const BOOL nationalDex
         encDataGroup = 10;
     }
 
-    narc = NARC_AllocAtEndAndReadWholeMemberByIndexPair(NARC_INDEX_ARC__ENCDATA_EX, encDataGroup, HEAP_ID_FIELD1);
-    encounterIndex = ((dailyMon >> (5 * areaNum)) & 0x1f);
+    int *narc = NARC_AllocAtEndAndReadWholeMemberByIndexPair(NARC_INDEX_ARC__ENCDATA_EX, encDataGroup, HEAP_ID_FIELD1);
+    u8 encounterIndex = ((dailyMon >> (5 * areaNum)) & 0x1f);
     encounterIndex %= 32;
 
     (*encounterSlot1) = narc[encounterIndex];
@@ -31,11 +29,11 @@ void ReplaceGreatMarshDailyEncounters(const int dailyMon, const BOOL nationalDex
     Heap_Free(narc);
 }
 
-static u8 GreatMarsh_GetAreaNumFromMapId(const int mapId)
+static u8 GreatMarsh_GetAreaNumFromMapId(const enum MapHeaderID mapHeaderID)
 {
     u8 areaNum = 0;
 
-    switch (mapId) {
+    switch (mapHeaderID) {
     case MAP_HEADER_GREAT_MARSH_1:
         areaNum = 0;
         break;
diff --git a/src/overlay006/npc_trade.c b/src/overlay006/npc_trade.c
index f82b61da88..af6c8384c5 100644
--- a/src/overlay006/npc_trade.c
+++ b/src/overlay006/npc_trade.c
@@ -80,7 +80,7 @@ void NPCTrade_FillAnimationTemplate(FieldSystem *fieldSystem, NPCTradeData *data
     Pokemon *partyMon = Party_GetPokemonBySlotIndex(party, slot);
     u32 level = Pokemon_GetValue(partyMon, MON_DATA_LEVEL, NULL);
 
-    NPCTrade_CreateMon(data->mon, data->npcTradeMon, level, data->npcTradeID, data->heapID, fieldSystem->location->mapId);
+    NPCTrade_CreateMon(data->mon, data->npcTradeMon, level, data->npcTradeID, data->heapID, fieldSystem->location->mapHeaderID);
 
     Pokemon_Copy(partyMon, givingMon);
     Pokemon_Copy(data->mon, receivingMon);
diff --git a/src/overlay006/roamer_after_battle.c b/src/overlay006/roamer_after_battle.c
index c1ac745f89..b8bfd69034 100644
--- a/src/overlay006/roamer_after_battle.c
+++ b/src/overlay006/roamer_after_battle.c
@@ -50,10 +50,10 @@ void RoamerAfterBattle_UpdateRoamers(FieldSystem *fieldSystem, FieldBattleDTO *b
             Roamer_SetData(roamer, ROAMER_DATA_STATUS, roamerStatus);
         }
 
-        MoveRoamersOffMap(specialEncounter, fieldSystem->location->mapId); // all roamers leave if you encounter one
+        MoveRoamersOffMap(specialEncounter, fieldSystem->location->mapHeaderID); // all roamers leave if you encounter one
     } else {
         if (LCRNG_RandMod(100) < 30) { // 30% chance for roamers to leave even if you don't encounter one
-            MoveRoamersOffMap(specialEncounter, fieldSystem->location->mapId);
+            MoveRoamersOffMap(specialEncounter, fieldSystem->location->mapHeaderID);
         }
     }
 }
diff --git a/src/overlay006/wild_encounters.c b/src/overlay006/wild_encounters.c
index 1f7f4d36cf..ebfbabce6a 100644
--- a/src/overlay006/wild_encounters.c
+++ b/src/overlay006/wild_encounters.c
@@ -199,7 +199,7 @@ static void WildEncounters_ReplaceSwarmEncounters(FieldSystem *fieldSystem, cons
     if (SpecialEncounter_IsSwarmEnabled(specialEncounter)) {
         u32 swarmId = SpecialEncounter_GetDailyMon(specialEncounter, DAILY_SWARM);
 
-        if (fieldSystem->location->mapId == Swarm_GetMapId(swarmId)) {
+        if (fieldSystem->location->mapHeaderID == Swarm_GetMapId(swarmId)) {
             *radarSlot1 = encounterData->swarmEncounters[0];
             *radarSlot2 = encounterData->swarmEncounters[1];
         }
@@ -208,7 +208,7 @@ static void WildEncounters_ReplaceSwarmEncounters(FieldSystem *fieldSystem, cons
 
 static void WildEncounters_ReplaceTrophyGardenEncounters(FieldSystem *fieldSystem, const BOOL nationalDexObtained, int *trophySlot1, int *trophySlot2)
 {
-    if (MapHeader_IsTrophyGarden(fieldSystem->location->mapId)) {
+    if (MapHeader_IsTrophyGarden(fieldSystem->location->mapHeaderID)) {
         u16 index1, index2;
         SpecialEncounter_GetTrophyGardenMons(fieldSystem->saveData, &index1, &index2);
 
@@ -404,7 +404,7 @@ BOOL WildEncounters_TryFishingEncounter(FieldSystem *fieldSystem, enum Encounter
     FieldBattleDTO_Init(*battleParams, fieldSystem);
     FieldBattleDTO_SetWaterTerrain(*battleParams);
 
-    if (MapHeader_HasFeebasTiles(fieldSystem->location->mapId) && PlayerAvatar_IsFacingFeebasTile(fieldSystem)) {
+    if (MapHeader_HasFeebasTiles(fieldSystem->location->mapHeaderID) && PlayerAvatar_IsFacingFeebasTile(fieldSystem)) {
         int species;
         u8 maxLevel, minLevel;
 
@@ -1390,7 +1390,7 @@ static void CreateWildSingleBattle(FieldSystem *fieldSystem, const BOOL safariGa
 static void WildEncounters_ReplaceGreatMarshDailyEncounters(FieldSystem *fieldSystem, const BOOL safariGameActive, const BOOL nationalDexObtained, EncounterSlot *encTable)
 {
     if (safariGameActive) {
-        ReplaceGreatMarshDailyEncounters(SpecialEncounter_GetDailyMon(SaveData_GetSpecialEncounters(fieldSystem->saveData), DAILY_MARSH), nationalDexObtained, fieldSystem->location->mapId, &encTable[6].species, &encTable[7].species);
+        ReplaceGreatMarshDailyEncounters(SpecialEncounter_GetDailyMon(SaveData_GetSpecialEncounters(fieldSystem->saveData), DAILY_MARSH), nationalDexObtained, fieldSystem->location->mapHeaderID, &encTable[6].species, &encTable[7].species);
     }
 }
 
@@ -1430,7 +1430,7 @@ static BOOL TryEncounterRoamer(FieldSystem *fieldSystem, Roamer **encounteredRoa
     for (u8 slot = 0; slot < ROAMING_SLOT_MAX; slot++) {
         int roamerMapId = RoamingPokemon_GetRouteFromId(SpecialEncounter_GetRoamerRouteIndex(speEnc, slot));
 
-        if (SpecialEncounter_IsRoamerActive(speEnc, slot) && roamerMapId == fieldSystem->location->mapId) {
+        if (SpecialEncounter_IsRoamerActive(speEnc, slot) && roamerMapId == fieldSystem->location->mapHeaderID) {
             roamers[numRoamersOnMap] = SpecialEncounter_GetRoamer(speEnc, slot);
             numRoamersOnMap++;
         }
diff --git a/src/overlay007/shop_menu.c b/src/overlay007/shop_menu.c
index 293c5c29c8..66a19bdb54 100644
--- a/src/overlay007/shop_menu.c
+++ b/src/overlay007/shop_menu.c
@@ -456,9 +456,9 @@ static u8 Shop_Exit(FieldSystem *fieldSystem, ShopMenu *shopMenu)
         StringTemplate_Free(shopMenu->strTemplate);
         String_Free(shopMenu->string);
 
-        if (shopMenu->martType == MART_TYPE_NORMAL && MapHeader_GetMapLabelTextID(fieldSystem->location->mapId) != LocationNames_Text_VeilstoneStore
-            && fieldSystem->location->mapId != MAP_HEADER_ETERNA_CITY_HERB_SHOP
-            && fieldSystem->location->mapId != MAP_HEADER_CELESTIC_TOWN_NORTHWEST_HOUSE) {
+        if (shopMenu->martType == MART_TYPE_NORMAL && MapHeader_GetMapLabelTextID(fieldSystem->location->mapHeaderID) != LocationNames_Text_VeilstoneStore
+            && fieldSystem->location->mapHeaderID != MAP_HEADER_ETERNA_CITY_HERB_SHOP
+            && fieldSystem->location->mapHeaderID != MAP_HEADER_CELESTIC_TOWN_NORTHWEST_HOUSE) {
             if (shopMenu->itemPurchaseCount != 0 && shopMenu->itemSoldCount != 0) {
                 journalEntryLocationEvent = JournalEntry_CreateEventBusinessAtMart(HEAP_ID_FIELD2);
                 JournalEntry_SaveData(shopMenu->journalEntry, journalEntryLocationEvent, JOURNAL_LOCATION);
diff --git a/src/overlay008/gym_features.c b/src/overlay008/gym_features.c
index 2fa83459c8..64e3063b83 100644
--- a/src/overlay008/gym_features.c
+++ b/src/overlay008/gym_features.c
@@ -80,7 +80,10 @@
 #define ETERNA_GYM_FOUNTAIN_Z       19
 #define ETERNA_GYM_WIDTH            21
 
-#define ETERNA_CLOCK_NO_HOUR_HAND_JUMP { -1, -1, 2 }
+#define ETERNA_CLOCK_NO_HOUR_HAND_JUMP \
+    {                                  \
+        -1, -1, 2                      \
+    }
 
 // 0x1559 is close to, but not the closest integer to 1/12 of 0x10000. It is
 // used for the hour-positions of the clock hand expect for 3, 6, 9 and 12
@@ -332,7 +335,7 @@ typedef struct VeilstoneGym_BagAnimation {
 typedef int (*VeilstoneGymAnimationStateFunc)(VeilstoneGym_BagAnimation *);
 
 typedef struct HearthomeGymTrainerRoomLayout {
-    int mapID;
+    enum MapHeaderID mapHeaderID;
     int firstDoorID;
     int numExitDoors;
     int offsetX;
@@ -2593,7 +2596,7 @@ static void EternaGym_SetupCameraMoveAwayFromPlayer(FieldSystem *fieldSystem, Et
         cameraMan->moveXFirst = TRUE;
     }
 
-    cameraMan->cameraObj = MapObjectMan_AddMapObject(fieldSystem->mapObjMan, playerX, playerZ, 0, OBJ_EVENT_GFX_INVISIBLE, 0x0, fieldSystem->location->mapId);
+    cameraMan->cameraObj = MapObjectMan_AddMapObject(fieldSystem->mapObjMan, playerX, playerZ, 0, OBJ_EVENT_GFX_INVISIBLE, 0x0, fieldSystem->location->mapHeaderID);
 
     MapObject_RecalculateObjectHeight(cameraMan->cameraObj);
     MapObject_SetHidden(cameraMan->cameraObj, TRUE);
@@ -3061,7 +3064,7 @@ BOOL VeilstoneGym_DynamicMapFeaturesCheckCollision(FieldSystem *fieldSystem, con
 
 static MapObject *VeilstoneGym_CreateObject(FieldSystem *fieldSystem, int x, int z, BOOL isPunchingBag)
 {
-    MapObject *mapObj = MapObjectMan_AddMapObject(fieldSystem->mapObjMan, x, z, 0, OBJ_EVENT_GFX_INVISIBLE, MOVEMENT_TYPE_NONE, fieldSystem->location->mapId);
+    MapObject *mapObj = MapObjectMan_AddMapObject(fieldSystem->mapObjMan, x, z, 0, OBJ_EVENT_GFX_INVISIBLE, MOVEMENT_TYPE_NONE, fieldSystem->location->mapHeaderID);
 
     MapObject_SetLocalID(mapObj, VEILSTONE_GYM_OBJECT_LOCALID);
     MapObject_SetDataAt(mapObj, isPunchingBag, 0);
@@ -3593,7 +3596,7 @@ static void VeilstoneGym_InitCameraManager(FieldSystem *fieldSystem, VeilstoneGy
 
     cameraMan->playerX = x;
     cameraMan->playerZ = z;
-    cameraMan->cameraObj = MapObjectMan_AddMapObject(fieldSystem->mapObjMan, x, z, 0, OBJ_EVENT_GFX_INVISIBLE, MOVEMENT_TYPE_NONE, fieldSystem->location->mapId);
+    cameraMan->cameraObj = MapObjectMan_AddMapObject(fieldSystem->mapObjMan, x, z, 0, OBJ_EVENT_GFX_INVISIBLE, MOVEMENT_TYPE_NONE, fieldSystem->location->mapHeaderID);
 
     MapObject_RecalculateObjectHeight(cameraMan->cameraObj);
     MapObject_SetHidden(cameraMan->cameraObj, TRUE);
@@ -3688,7 +3691,7 @@ static void VeilstoneGym_UpdateCamera(VeilstoneGym_BagAnimation *bagAnim, fx32 s
 
 static const HearthomeGymTrainerRoomLayout sTrainerRoomLayouts[HEARTHOME_NUM_TRAINER_ROOMS] = {
     {
-        .mapID = MAP_HEADER_HEARTHOME_CITY_GYM_TRAINER_ROOM_1,
+        .mapHeaderID = MAP_HEADER_HEARTHOME_CITY_GYM_TRAINER_ROOM_1,
         .firstDoorID = HEARTHOME_DOOR_ID_CIRCLE,
         .numExitDoors = 3,
         .offsetX = 1,
@@ -3697,7 +3700,7 @@ static const HearthomeGymTrainerRoomLayout sTrainerRoomLayouts[HEARTHOME_NUM_TRA
         .sizeZ = HEARTHOME_ROOM_1_SIZE_Z,
     },
     {
-        .mapID = MAP_HEADER_HEARTHOME_CITY_GYM_TRAINER_ROOM_2,
+        .mapHeaderID = MAP_HEADER_HEARTHOME_CITY_GYM_TRAINER_ROOM_2,
         .firstDoorID = HEARTHOME_DOOR_ID_SUN,
         .numExitDoors = 5,
         .offsetX = 1,
@@ -3799,11 +3802,11 @@ void HearthomeGym_DynamicMapFeaturesInit(FieldSystem *fieldSystem)
     HearthomeGym_InitTrainers(gymSystem);
 
     int i = 0;
-    int mapID = fieldSystem->location->mapId;
+    enum MapHeaderID mapHeaderID = fieldSystem->location->mapHeaderID;
     const HearthomeGymTrainerRoomLayout *room = sTrainerRoomLayouts;
 
     do {
-        if (room->mapID == mapID) {
+        if (room->mapHeaderID == mapHeaderID) {
             break;
         }
 
@@ -3887,7 +3890,7 @@ static void HearthomeGym_InitFog(HearthomeGymSystem *gymSystem)
     char fogDensity = 109;
     if (TrainerInfo_HasBadge(SaveData_GetTrainerInfo(gymSystem->fieldSystem->saveData), BADGE_ID_RELIC) == TRUE) {
         fogDensity = 91;
-    } else if (gymSystem->fieldSystem->location->mapId == MAP_HEADER_HEARTHOME_CITY_GYM_TRAINER_ROOM_2) {
+    } else if (gymSystem->fieldSystem->location->mapHeaderID == MAP_HEADER_HEARTHOME_CITY_GYM_TRAINER_ROOM_2) {
         fogDensity = 119;
     }
 
@@ -4018,11 +4021,11 @@ BOOL HearthomeGym_CheckIfEnteredIncorrectDoor(FieldSystem *fieldSystem, int play
     }
 
     int i = 0;
-    int mapID = fieldSystem->location->mapId;
+    enum MapHeaderID mapHeaderID = fieldSystem->location->mapHeaderID;
     const HearthomeGymTrainerRoomLayout *room = sTrainerRoomLayouts;
 
     do {
-        if (room->mapID == mapID) {
+        if (room->mapHeaderID == mapHeaderID) {
             break;
         }
 
diff --git a/src/overlay009/ov9_02249960.c b/src/overlay009/ov9_02249960.c
index 81a2f62bab..fdbf78a11e 100644
--- a/src/overlay009/ov9_02249960.c
+++ b/src/overlay009/ov9_02249960.c
@@ -5492,7 +5492,7 @@ static int DistWorldElevatorPlatform_ChangeMaps(DistWorldSystem *system, DistWor
             MapObject_SetScript(elevatorPlatform->passengerMapObj, 6);
         }
 
-        MapObject_SetMapID(elevatorPlatform->passengerMapObj, elevatorPlatform->destMapHeaderID);
+        MapObject_SetMapHeaderID(elevatorPlatform->passengerMapObj, elevatorPlatform->destMapHeaderID);
     }
 
     if (elevatorPlatform->dir == MOVING_PLATFORM_ELEVATOR_DIR_DOWN) {
@@ -7288,7 +7288,7 @@ static MapObject *FindExistingMapObjectByEvent(DistWorldSystem *system, const Ob
     const MapObjectManager *mapObjMan = system->fieldSystem->mapObjMan;
 
     while (MapObjectMan_FindObjectWithStatus(mapObjMan, &mapObj, &startIdx, MAP_OBJ_STATUS_0)) {
-        if (MapObject_GetMapID(mapObj) == mapHeaderID && MapObject_GetLocalID(mapObj) == objEvent->localID) {
+        if (MapObject_GetMapHeaderID(mapObj) == mapHeaderID && MapObject_GetLocalID(mapObj) == objEvent->localID) {
             GF_ASSERT(objEvent->graphicsID == MapObject_GetGraphicsID(mapObj));
             return mapObj;
         }
@@ -7390,7 +7390,7 @@ static void DeleteMapObjectsForMap(DistWorldSystem *system, u32 mapHeaderID)
 
     for (i = 0; i < MAP_OBJECT_MANAGER_OBJECT_COUNT; i++, iter++) {
         if (*iter != NULL) {
-            if (MapObject_GetMapID(*iter) == mapHeaderID) {
+            if (MapObject_GetMapHeaderID(*iter) == mapHeaderID) {
                 MapObject_Delete(*iter);
                 *iter = NULL;
             }
@@ -7434,7 +7434,7 @@ static MapObject *AddMapObjectWithLocalID(DistWorldSystem *system, u32 mapHeader
 
 void DistWorld_AddMapObjectWithLocalID(FieldSystem *fieldSystem, u16 mapObjLocalID)
 {
-    u32 mapHeaderID = fieldSystem->location->mapId;
+    u32 mapHeaderID = fieldSystem->location->mapHeaderID;
     DistWorldSystem *dwSystem = fieldSystem->unk_04->dynamicMapFeaturesData;
 
     AddMapObjectWithLocalID(dwSystem, mapHeaderID, mapObjLocalID);
@@ -7444,12 +7444,12 @@ void DistWorld_DeleteMapObjectWithLocalID(FieldSystem *fieldSystem, u16 mapObjLo
 {
     int startIdx = 0;
     MapObject *mapObj;
-    u32 mapHeaderID = fieldSystem->location->mapId;
+    u32 mapHeaderID = fieldSystem->location->mapHeaderID;
     MapObjectManager *mapObjMan = fieldSystem->mapObjMan;
     DistWorldSystem *dwSystem = fieldSystem->unk_04->dynamicMapFeaturesData;
 
     while (MapObjectMan_FindObjectWithStatus(mapObjMan, &mapObj, &startIdx, MAP_OBJ_STATUS_0) == TRUE) {
-        if (MapObject_GetLocalID(mapObj) == mapObjLocalID && MapObject_GetMapID(mapObj) == mapHeaderID) {
+        if (MapObject_GetLocalID(mapObj) == mapObjLocalID && MapObject_GetMapHeaderID(mapObj) == mapHeaderID) {
             DeleteMapObject(dwSystem, mapObj);
             return;
         }
@@ -7590,7 +7590,7 @@ static BOOL FindBoulderFallLocationFlag(u32 mapHeaderID, int boulderTileX, int b
 BOOL DistWorld_WillBoulderBeAtFallLocation(const MapObject *boulderMapObj, enum FaceDirection boulderDir)
 {
     FieldSystem *fieldSystem = MapObject_FieldSystem(boulderMapObj);
-    u32 mapHeaderID = fieldSystem->location->mapId;
+    u32 mapHeaderID = fieldSystem->location->mapHeaderID;
 
     int boulderTileX = MapObject_GetX(boulderMapObj);
     int boulderTileZ = MapObject_GetZ(boulderMapObj);
@@ -7604,7 +7604,7 @@ BOOL DistWorld_WillBoulderBeAtFallLocation(const MapObject *boulderMapObj, enum
 static BOOL FindMapObjectBoulderFallLocationFlag(const MapObject *boulderMapObj, u32 *flagIndex)
 {
     FieldSystem *fieldSystem = MapObject_FieldSystem(boulderMapObj);
-    u32 mapHeaderID = fieldSystem->location->mapId;
+    u32 mapHeaderID = fieldSystem->location->mapHeaderID;
 
     int boulderTileX = MapObject_GetX(boulderMapObj);
     int boulderTileZ = MapObject_GetZ(boulderMapObj);
@@ -7667,7 +7667,7 @@ static BOOL DistWorldFallingBoulder_TickToB6F(DistWorldFallingBoulder *boulder)
     Sound_PlayEffect(SEQ_SE_DP_UG_008);
     boulderPos.y = MAP_OBJECT_COORD_EDGE_TO_FX32(115);
     MapObject_SetPosDirFromVec(boulderMapObj, &boulderPos, MapObject_GetFacingDir(boulderMapObj));
-    MapObject_SetMapID(boulderMapObj, MAP_HEADER_DISTORTION_WORLD_B6F);
+    MapObject_SetMapHeaderID(boulderMapObj, MAP_HEADER_DISTORTION_WORLD_B6F);
 
     u32 flagIndexToSet;
     u32 flagIndexToClear;
@@ -9727,7 +9727,7 @@ void DistWorld_LoadFloorOffsets(int mapHeaderID, int *offsetTileX, int *offsetAl
 
 static u32 DistWorldSystem_GetMapHeaderID(DistWorldSystem *system)
 {
-    return system->fieldSystem->location->mapId;
+    return system->fieldSystem->location->mapHeaderID;
 }
 
 static enum AvatarDistortionState GetAvatarDistortionStateForFloatingPlatformKind(u32 platformKind)
diff --git a/src/platform_lift.c b/src/platform_lift.c
index 83756ff6b3..2811956b57 100644
--- a/src/platform_lift.c
+++ b/src/platform_lift.c
@@ -209,7 +209,7 @@ void PersistedMapFeatures_InitForPlatformLift(FieldSystem *fieldSystem)
     data->notUsedWhenEnteredMap = TRUE;
     data->kind = PLATFORM_LIFT_KIND_IRON_ISLAND;
 
-    switch (fieldSystem->location->mapId) {
+    switch (fieldSystem->location->mapHeaderID) {
     case MAP_HEADER_IRON_ISLAND_B1F_RIGHT_ROOM:
         if (fieldSystem->location->z == IRON_ISLAND_B1F_RIGHT_ROOM_BOTTOM_FLOOR_WARP_Z) {
             data->floorID = PLATFORM_LIFT_BOTTOM_FLOOR;
diff --git a/src/pokeradar.c b/src/pokeradar.c
index 3f23eb7656..6b76a79fec 100644
--- a/src/pokeradar.c
+++ b/src/pokeradar.c
@@ -136,7 +136,7 @@ BOOL RadarSpawnPatches(FieldSystem *fieldSystem, const int param1, const int par
 
     if (v7 == 0) {
         RadarChain_Clear(chain);
-        FieldBGM_TryFadeOut(fieldSystem, FieldBGM_GetEffective(fieldSystem, fieldSystem->location->mapId), 1);
+        FieldBGM_TryFadeOut(fieldSystem, FieldBGM_GetEffective(fieldSystem, fieldSystem->location->mapHeaderID), 1);
     } else {
         chain->active = TRUE;
     }
@@ -289,7 +289,7 @@ void PokeRadar_ClearIfAllOutOfView(FieldSystem *fieldSystem)
 
     if (inactiveRadarRings == 4) {
         RadarChain_Clear(fieldSystem->chain);
-        FieldBGM_TryFadeOut(fieldSystem, FieldBGM_GetEffective(fieldSystem, fieldSystem->location->mapId), 1);
+        FieldBGM_TryFadeOut(fieldSystem, FieldBGM_GetEffective(fieldSystem, fieldSystem->location->mapHeaderID), 1);
     }
 }
 
@@ -320,7 +320,7 @@ static BOOL CheckTileIsGrass(FieldSystem *fieldSystem, const fx32 param1, const
         int v5 = v0 / 32;
         int v6 = v1 / 32;
         int v4 = MapMatrix_GetMapHeaderIDAtCoords(fieldSystem->mapMatrix, v5, v6);
-        if (fieldSystem->location->mapId != v4) {
+        if (fieldSystem->location->mapHeaderID != v4) {
             patch->active = FALSE;
             return FALSE;
         }
diff --git a/src/scrcmd.c b/src/scrcmd.c
index 57e09a8411..d53f0336ab 100644
--- a/src/scrcmd.c
+++ b/src/scrcmd.c
@@ -107,6 +107,7 @@
 #include "field_bgm.h"
 #include "field_comm_manager.h"
 #include "field_map_change.h"
+#include "field_map_change_flags.h"
 #include "field_message.h"
 #include "field_overworld_state.h"
 #include "field_script_context.h"
@@ -209,7 +210,6 @@
 #include "unk_0205DFC4.h"
 #include "unk_020655F4.h"
 #include "unk_02069BE0.h"
-#include "unk_02070428.h"
 #include "unk_020722AC.h"
 #include "unk_0207DA28.h"
 #include "unk_02097B18.h"
@@ -2348,7 +2348,7 @@ static BOOL ScrCmd_AddObject(ScriptContext *ctx)
     FieldSystem *fieldSystem = ctx->fieldSystem;
     u16 localID = ScriptContext_GetVar(ctx);
 
-    MapObject *mapObj = MapObjectMan_AddMapObjectFromLocalID(fieldSystem->mapObjMan, localID, MapHeaderData_GetNumObjectEvents(fieldSystem), fieldSystem->location->mapId, MapHeaderData_GetObjectEvents(fieldSystem));
+    MapObject *mapObj = MapObjectMan_AddMapObjectFromLocalID(fieldSystem->mapObjMan, localID, MapHeaderData_GetNumObjectEvents(fieldSystem), fieldSystem->location->mapHeaderID, MapHeaderData_GetObjectEvents(fieldSystem));
 
     if (mapObj == NULL) {
         GF_ASSERT(FALSE);
@@ -2378,7 +2378,7 @@ static BOOL ScrCmd_AddFreeCamera(ScriptContext *ctx)
     u16 zPos = ScriptContext_GetVar(ctx);
     MapObject **cameraObject = FieldSystem_GetScriptMemberPtr(ctx->fieldSystem, SCRIPT_MANAGER_CAMERA_OBJECT);
 
-    *cameraObject = MapObjectMan_AddMapObject(ctx->fieldSystem->mapObjMan, xPos, zPos, 0, OBJ_EVENT_GFX_INVISIBLE, 0x0, ctx->fieldSystem->location->mapId);
+    *cameraObject = MapObjectMan_AddMapObject(ctx->fieldSystem->mapObjMan, xPos, zPos, 0, OBJ_EVENT_GFX_INVISIBLE, 0x0, ctx->fieldSystem->location->mapHeaderID);
 
     MapObject_RecalculateObjectHeight(*cameraObject);
     MapObject_SetHidden(*cameraObject, TRUE);
@@ -2414,7 +2414,7 @@ static BOOL ScrCmd_AddCameraOverrideObject(ScriptContext *ctx)
     u16 zPos = ScriptContext_GetVar(ctx);
     MapObject **cameraObject = FieldSystem_GetScriptMemberPtr(ctx->fieldSystem, SCRIPT_MANAGER_CAMERA_OBJECT);
 
-    *cameraObject = MapObjectMan_AddMapObject(ctx->fieldSystem->mapObjMan, xPos, zPos, 0, OBJ_EVENT_GFX_INVISIBLE, 0x0, ctx->fieldSystem->location->mapId);
+    *cameraObject = MapObjectMan_AddMapObject(ctx->fieldSystem->mapObjMan, xPos, zPos, 0, OBJ_EVENT_GFX_INVISIBLE, 0x0, ctx->fieldSystem->location->mapHeaderID);
 
     MapObject_RecalculateObjectHeight(*cameraObject);
     MapObject_SetHidden(*cameraObject, TRUE);
@@ -3568,13 +3568,13 @@ static BOOL ScriptContext_ScreenWipeDone(ScriptContext *ctx)
 
 static BOOL ScrCmd_Warp(ScriptContext *ctx)
 {
-    u16 mapID = ScriptContext_GetVar(ctx);
+    enum MapHeaderID mapHeaderID = ScriptContext_GetVar(ctx);
     s16 unused = ScriptContext_ReadHalfWord(ctx);
     u16 x = ScriptContext_GetVar(ctx);
     u16 z = ScriptContext_GetVar(ctx);
     u16 direction = ScriptContext_GetVar(ctx);
 
-    FieldTask_StartMapChangeFull(ctx->task, mapID, -1, x, z, direction);
+    FieldTask_StartMapChangeFull(ctx->task, mapHeaderID, -1, x, z, direction);
     return TRUE;
 }
 
@@ -3606,7 +3606,7 @@ static BOOL ScrCmd_GetPreviousMapID(ScriptContext *ctx)
     Location *location = FieldOverworldState_GetPrevLocation(fieldState);
     u16 *mapId = ScriptContext_GetVarPointer(ctx);
 
-    *mapId = location->mapId;
+    *mapId = location->mapHeaderID;
     return FALSE;
 }
 
@@ -3614,7 +3614,7 @@ static BOOL ScrCmd_GetCurrentMapID(ScriptContext *ctx)
 {
     u16 *mapID = ScriptContext_GetVarPointer(ctx);
 
-    *mapID = ctx->fieldSystem->location->mapId;
+    *mapID = ctx->fieldSystem->location->mapHeaderID;
     return FALSE;
 }
 
@@ -3727,7 +3727,7 @@ static BOOL ScrCmd_SetPlayerBike(ScriptContext *ctx)
         PlayerAvatar_SetTransitionState(ctx->fieldSystem->playerAvatar, PLAYER_TRANSITION_WALKING);
         PlayerAvatar_RequestChangeState(ctx->fieldSystem->playerAvatar);
         FieldBGM_SetOverride(ctx->fieldSystem, SEQ_NONE);
-        FieldBGM_TryFadeOut(ctx->fieldSystem, FieldBGM_GetEffective(ctx->fieldSystem, ctx->fieldSystem->location->mapId), 1);
+        FieldBGM_TryFadeOut(ctx->fieldSystem, FieldBGM_GetEffective(ctx->fieldSystem, ctx->fieldSystem->location->mapHeaderID), 1);
     }
 
     return FALSE;
@@ -3902,7 +3902,7 @@ static BOOL ScrCmd_SetSpecialLocation(ScriptContext *ctx)
 {
     Location location;
 
-    location.mapId = ScriptContext_GetVar(ctx);
+    location.mapHeaderID = ScriptContext_GetVar(ctx);
     location.warpId = ScriptContext_GetVar(ctx);
     location.x = ScriptContext_GetVar(ctx);
     location.z = ScriptContext_GetVar(ctx);
@@ -3918,7 +3918,7 @@ static BOOL ScrCmd_GetFloorsAbove(ScriptContext *ctx)
     u16 *destVar = ScriptContext_GetVarPointer(ctx);
 
     location = FieldOverworldState_GetSpecialLocation(SaveData_GetFieldOverworldState(ctx->fieldSystem->saveData));
-    *destVar = FieldMenu_GetFloorsAbove(location->mapId);
+    *destVar = FieldMenu_GetFloorsAbove(location->mapHeaderID);
 
     return FALSE;
 }
@@ -5559,11 +5559,11 @@ static BOOL ScrCmd_PlayBoatCutscene(ScriptContext *ctx)
 {
     u8 travelDir = ScriptContext_ReadByte(ctx);
     u8 exitDir = ScriptContext_ReadByte(ctx);
-    int mapID = ScriptContext_ReadHalfWord(ctx);
+    enum MapHeaderID mapHeaderID = ScriptContext_ReadHalfWord(ctx);
     int x = ScriptContext_ReadHalfWord(ctx);
     int z = ScriptContext_ReadHalfWord(ctx);
 
-    FieldSystem_PlayBoatCutscene(ctx->fieldSystem, travelDir, exitDir, mapID, x, z);
+    FieldSystem_PlayBoatCutscene(ctx->fieldSystem, travelDir, exitDir, mapHeaderID, x, z);
     return TRUE;
 }
 
@@ -6504,7 +6504,7 @@ static BOOL ScrCmd_2B5(ScriptContext *ctx)
     FieldOverworldState *fieldState = SaveData_GetFieldOverworldState(ctx->fieldSystem->saveData);
     Location *location = FieldOverworldState_GetExitLocation(fieldState);
 
-    location->mapId = mapId;
+    location->mapHeaderID = mapId;
     location->x = x;
     location->z = z;
     location->warpId = WARP_ID_NONE;
@@ -6565,7 +6565,7 @@ static BOOL ScrCmd_CloseSaveInfo(ScriptContext *ctx)
 
 static BOOL ScrCmd_Unused_2C3(ScriptContext *ctx)
 {
-    sub_02070428(ctx->fieldSystem, ScriptContext_ReadByte(ctx));
+    FieldSystem_SetTemporaryMapChange(ctx->fieldSystem, ScriptContext_ReadByte(ctx));
     return FALSE;
 }
 
@@ -6588,7 +6588,7 @@ static BOOL ScrCmd_LaunchBattleFrontierScene(ScriptContext *ctx)
     fieldData->options = SaveData_GetOptions(ctx->fieldSystem->saveData);
     fieldData->sceneID = sceneID;
     fieldData->saveData = ctx->fieldSystem->saveData;
-    fieldData->mapHeaderID = ctx->fieldSystem->location->mapId;
+    fieldData->mapHeaderID = ctx->fieldSystem->location->mapHeaderID;
     fieldData->journalEntry = ctx->fieldSystem->journalEntry;
     fieldData->bagCursor = ctx->fieldSystem->bagCursor;
     fieldData->subscreenCursorOn = ctx->fieldSystem->battleSubscreenCursorOn;
diff --git a/src/scrcmd_contests.c b/src/scrcmd_contests.c
index b953686439..eac8b56341 100644
--- a/src/scrcmd_contests.c
+++ b/src/scrcmd_contests.c
@@ -96,7 +96,7 @@ BOOL ScrCmd_EndContest(ScriptContext *ctx)
 {
     void **contest = FieldSystem_GetScriptMemberPtr(ctx->fieldSystem, SCRIPT_MANAGER_DATA_PTR);
     u16 unused = ScriptContext_GetVar(ctx);
-    u32 mapID = MapHeader_GetMapLabelTextID(ctx->fieldSystem->location->mapId);
+    u32 mapID = MapHeader_GetMapLabelTextID(ctx->fieldSystem->location->mapHeaderID);
 
     Contest_EndContest(*contest, ctx->fieldSystem->saveData, mapID, ctx->fieldSystem->journalEntry);
     Contest_Free(*contest);
diff --git a/src/scrcmd_party.c b/src/scrcmd_party.c
index 0913f451cd..49d000e7c6 100644
--- a/src/scrcmd_party.c
+++ b/src/scrcmd_party.c
@@ -28,7 +28,7 @@
 
 BOOL ScrCmd_GivePokemon(ScriptContext *ctx)
 {
-    int metLocation = MapHeader_GetMapLabelTextID(ctx->fieldSystem->location->mapId);
+    int metLocation = MapHeader_GetMapLabelTextID(ctx->fieldSystem->location->mapHeaderID);
     int metTerrain = TERRAIN_MAX;
     FieldSystem *fieldSystem = ctx->fieldSystem;
     u16 species = ScriptContext_GetVar(ctx);
@@ -280,7 +280,7 @@ BOOL ScrCmd_IncreasePartyMonFriendship(ScriptContext *ctx)
     FieldSystem *fieldSystem = ctx->fieldSystem;
     u16 value = ScriptContext_GetVar(ctx);
     u16 slot = ScriptContext_GetVar(ctx);
-    u32 location = MapHeader_GetMapLabelTextID(ctx->fieldSystem->location->mapId);
+    u32 location = MapHeader_GetMapLabelTextID(ctx->fieldSystem->location->mapHeaderID);
 
     Pokemon *mon = Party_GetPokemonBySlotIndex(SaveData_GetParty(fieldSystem->saveData), slot);
     u16 friendship = Pokemon_GetValue(mon, MON_DATA_FRIENDSHIP, NULL);
diff --git a/src/scrcmd_sound.c b/src/scrcmd_sound.c
index 37c7283752..93c1aecaed 100644
--- a/src/scrcmd_sound.c
+++ b/src/scrcmd_sound.c
@@ -42,7 +42,7 @@ BOOL ScrCmd_StopMusic(ScriptContext *ctx)
 
 BOOL ScrCmd_PlayDefaultMusic(ScriptContext *ctx)
 {
-    Sound_PlayBGM(FieldBGM_GetForMapHeader(ctx->fieldSystem, ctx->fieldSystem->location->mapId));
+    Sound_PlayBGM(FieldBGM_GetForMapHeader(ctx->fieldSystem, ctx->fieldSystem->location->mapHeaderID));
     return FALSE;
 }
 
diff --git a/src/script_manager.c b/src/script_manager.c
index 5a96a35b95..3a12f178d4 100644
--- a/src/script_manager.c
+++ b/src/script_manager.c
@@ -263,9 +263,9 @@ static void ScriptContext_Load(FieldSystem *fieldSystem, ScriptContext *ctx, int
 
 static void ScriptContext_LoadFromCurrentMap(FieldSystem *fieldSystem, ScriptContext *ctx)
 {
-    u8 *scripts = ScriptContext_LoadScripts(fieldSystem->location->mapId);
+    u8 *scripts = ScriptContext_LoadScripts(fieldSystem->location->mapHeaderID);
     ctx->scripts = scripts;
-    ctx->loader = MessageLoader_Init(MSG_LOADER_LOAD_ON_DEMAND, NARC_INDEX_MSGDATA__PL_MSG, MapHeaderToMsgArchive(fieldSystem->location->mapId), HEAP_ID_FIELD2);
+    ctx->loader = MessageLoader_Init(MSG_LOADER_LOAD_ON_DEMAND, NARC_INDEX_MSGDATA__PL_MSG, MapHeaderToMsgArchive(fieldSystem->location->mapHeaderID), HEAP_ID_FIELD2);
 }
 
 void *ScriptManager_GetMemberPtr(ScriptManager *scriptManager, u32 member)
@@ -559,17 +559,17 @@ void FieldSystem_ClearDailyHiddenItemFlags(FieldSystem *fieldSystem)
 {
     u8 rand = LCRNG_Next() % NELEMS(sIronIslandHiddenItemFlags);
 
-    if (fieldSystem->location->mapId != sIronIslandHiddenItemFlags[rand][0]) {
+    if (fieldSystem->location->mapHeaderID != sIronIslandHiddenItemFlags[rand][0]) {
         FieldSystem_ClearFlag(fieldSystem, HIDDEN_ITEM_FLAGS_START + sIronIslandHiddenItemFlags[rand][1]);
     }
 
     rand = LCRNG_Next() % NELEMS(sIronIslandHiddenItemFlags);
 
-    if (fieldSystem->location->mapId != sIronIslandHiddenItemFlags[rand][0]) {
+    if (fieldSystem->location->mapHeaderID != sIronIslandHiddenItemFlags[rand][0]) {
         FieldSystem_ClearFlag(fieldSystem, HIDDEN_ITEM_FLAGS_START + sIronIslandHiddenItemFlags[rand][1]);
     }
 
-    if (fieldSystem->location->mapId != MAP_HEADER_FLOAROMA_MEADOW) {
+    if (fieldSystem->location->mapHeaderID != MAP_HEADER_FLOAROMA_MEADOW) {
         rand = LCRNG_Next() % NELEMS(sFloaromaMeadowHiddenItemFlags);
         FieldSystem_ClearFlag(fieldSystem, HIDDEN_ITEM_FLAGS_START + sFloaromaMeadowHiddenItemFlags[rand]);
 
diff --git a/src/spawn_locations.c b/src/spawn_locations.c
index 232c62430a..1c5a368e1f 100644
--- a/src/spawn_locations.c
+++ b/src/spawn_locations.c
@@ -4,6 +4,7 @@
 #include <string.h>
 
 #include "generated/first_arrival_to_zones.h"
+#include "generated/map_headers.h"
 
 #include "field/field_system.h"
 
@@ -13,10 +14,10 @@
 #include "vars_flags.h"
 
 typedef struct SpawnLocation {
-    u16 blackOutMapId;
+    u16 blackOutMapHeaderID;
     u16 blackOutX;
     u16 blackOutZ;
-    u16 flyMapId;
+    u16 flyMapHeaderID;
     u16 flyX;
     u16 flyZ;
     u8 isWarpPos;
@@ -67,7 +68,7 @@ void Location_InitFly(int flyDestination, Location *location)
 {
     flyDestination = MapSpawnIdToIndex(flyDestination);
 
-    location->mapId = sSpawnLocations[flyDestination].flyMapId;
+    location->mapHeaderID = sSpawnLocations[flyDestination].flyMapHeaderID;
     location->warpId = WARP_ID_NONE;
     location->x = sSpawnLocations[flyDestination].flyX;
     location->z = sSpawnLocations[flyDestination].flyZ;
@@ -78,17 +79,17 @@ void Location_InitBlackOut(int blackOutDestination, Location *location)
 {
     blackOutDestination = MapSpawnIdToIndex(blackOutDestination);
 
-    location->mapId = sSpawnLocations[blackOutDestination].blackOutMapId;
+    location->mapHeaderID = sSpawnLocations[blackOutDestination].blackOutMapHeaderID;
     location->warpId = WARP_ID_NONE;
     location->x = sSpawnLocations[blackOutDestination].blackOutX;
     location->z = sSpawnLocations[blackOutDestination].blackOutZ;
     location->faceDirection = FACE_UP;
 }
 
-int GetMapBlackOutWarpId(int mapId)
+int GetMapBlackOutWarpId(enum MapHeaderID mapHeaderID)
 {
     for (int i = 0; i < NELEMS(sSpawnLocations); i++) {
-        if (sSpawnLocations[i].blackOutMapId == mapId && sSpawnLocations[i].isWarpPos) {
+        if (sSpawnLocations[i].blackOutMapHeaderID == mapHeaderID && sSpawnLocations[i].isWarpPos) {
             return i + 1;
         }
     }
@@ -96,10 +97,10 @@ int GetMapBlackOutWarpId(int mapId)
     return 0;
 }
 
-int GetMapFlyWarpId(int mapId)
+int GetMapFlyWarpId(enum MapHeaderID mapHeaderID)
 {
     for (int i = 0; i < NELEMS(sSpawnLocations); i++) {
-        if (sSpawnLocations[i].flyMapId == mapId && sSpawnLocations[i].isWarpPos) {
+        if (sSpawnLocations[i].flyMapHeaderID == mapHeaderID && sSpawnLocations[i].isWarpPos) {
             return i + 1;
         }
     }
@@ -107,7 +108,7 @@ int GetMapFlyWarpId(int mapId)
     return 0;
 }
 
-int GetSpawnIdByMapAndCoords(int mapID, int param1, int param2)
+int GetSpawnIdByMapAndCoords(enum MapHeaderID mapHeaderID, int param1, int param2)
 {
     int i;
     int v1 = param1 / 32;
@@ -115,7 +116,7 @@ int GetSpawnIdByMapAndCoords(int mapID, int param1, int param2)
     int destinationId = 0;
 
     for (i = 0; i < NELEMS(sSpawnLocations); i++) {
-        if (sSpawnLocations[i].flyMapId == mapID) {
+        if (sSpawnLocations[i].flyMapHeaderID == mapHeaderID) {
             destinationId = i + 1;
 
             if ((v1 == sSpawnLocations[i].flyX / 32) && (v2 == sSpawnLocations[i].flyZ / 32)) {
@@ -127,20 +128,18 @@ int GetSpawnIdByMapAndCoords(int mapID, int param1, int param2)
     return destinationId;
 }
 
-void TryUnlockFlyLocationByMap(FieldSystem *fieldSystem, int param1)
+void TryUnlockFlyLocationByMap(FieldSystem *fieldSystem, enum MapHeaderID mapHeaderID)
 {
-    int v0;
-
-    for (v0 = 0; v0 < NELEMS(sSpawnLocations); v0++) {
-        if ((sSpawnLocations[v0].flyMapId == param1) && sSpawnLocations[v0].unlockOnMapEntry) {
+    for (int v0 = 0; v0 < NELEMS(sSpawnLocations); v0++) {
+        if ((sSpawnLocations[v0].flyMapHeaderID == mapHeaderID) && sSpawnLocations[v0].unlockOnMapEntry) {
             SystemFlag_HandleFirstArrivalToZone(SaveData_GetVarsFlags(fieldSystem->saveData), HANDLE_FLAG_SET, sSpawnLocations[v0].firstArrival);
             return;
         }
     }
 }
 
-BOOL CheckFlyLocationUnlocked(FieldSystem *fieldSystem, int param1)
+BOOL CheckFlyLocationUnlocked(FieldSystem *fieldSystem, int flyLocation)
 {
-    int v0 = MapSpawnIdToIndex(param1);
-    return SystemFlag_HandleFirstArrivalToZone(SaveData_GetVarsFlags(fieldSystem->saveData), HANDLE_FLAG_CHECK, sSpawnLocations[v0].firstArrival);
+    int flyDestination = MapSpawnIdToIndex(flyLocation);
+    return SystemFlag_HandleFirstArrivalToZone(SaveData_GetVarsFlags(fieldSystem->saveData), HANDLE_FLAG_CHECK, sSpawnLocations[flyDestination].firstArrival);
 }
diff --git a/src/start_menu.c b/src/start_menu.c
index 12201fd774..f8a17774f6 100644
--- a/src/start_menu.c
+++ b/src/start_menu.c
@@ -260,7 +260,7 @@ static const u8 sOnlyMovePages[] = {
 
 BOOL FieldSystem_IsInValidLocation(FieldSystem *fieldSystem)
 {
-    return MapHeader_GetMapLabelTextID(fieldSystem->location->mapId) != LocationNames_Text_MysteryZone;
+    return MapHeader_GetMapLabelTextID(fieldSystem->location->mapHeaderID) != LocationNames_Text_MysteryZone;
 }
 
 #define HIDE_OPTION_POKEDEX      (1 << 0)
@@ -376,7 +376,7 @@ static u32 StartMenu_GetNormalHiddenOptions(FieldSystem *fieldSystem)
         hideFlags |= HIDE_OPTION_BAG;
     }
 
-    if (MapHeader_IsAmitySquare(fieldSystem->location->mapId) == TRUE) {
+    if (MapHeader_IsAmitySquare(fieldSystem->location->mapHeaderID) == TRUE) {
         hideFlags |= HIDE_OPTION_POKEMON;
         hideFlags |= HIDE_OPTION_BAG;
     }
@@ -1081,7 +1081,7 @@ BOOL StartMenu_ExitPartyMenu(FieldTask *fieldTask)
     case PARTY_MENU_EXIT_CODE_EVOLVE_BY_LEVEL:
         evoData = Heap_Alloc(HEAP_ID_FIELD2, sizeof(MenuEvolutionData));
 
-        evoData->dummy = MapHeader_GetMapEvolutionMethod(fieldSystem->location->mapId);
+        evoData->dummy = MapHeader_GetMapEvolutionMethod(fieldSystem->location->mapHeaderID);
         evoData->class = EVO_CLASS_BY_LEVEL;
         evoData->slot = partyMenu->selectedMonSlot;
         evoData->targetSpecies = partyMenu->evoTargetSpecies;
@@ -1763,7 +1763,7 @@ static void StartMenu_Evolve(FieldTask *fieldTask)
         Heap_Destroy(HEAP_ID_EVOLUTION);
         Sound_StopBGM(SEQ_SHINKA, 0);
         Sound_SetScene(SOUND_SCENE_NONE);
-        FieldBGM_PlayEffectiveForMapHeader(fieldSystem, fieldSystem->location->mapId);
+        FieldBGM_PlayEffectiveForMapHeader(fieldSystem, fieldSystem->location->mapHeaderID);
 
         menu->taskData = FieldSystem_OpenBag(fieldSystem, &menu->itemUseCtx);
 
diff --git a/src/system_vars.c b/src/system_vars.c
index 927c54539c..e6ea14aff4 100644
--- a/src/system_vars.c
+++ b/src/system_vars.c
@@ -420,7 +420,7 @@ void SystemVars_UpdateVillaVisitor(SaveData *saveData)
     FieldOverworldState *fieldState = SaveData_GetFieldOverworldState(saveData);
     Location *location = FieldOverworldState_GetPlayerLocation(fieldState);
 
-    if (location->mapId != MAP_HEADER_RESORT_AREA && location->mapId != MAP_HEADER_VILLA) {
+    if (location->mapHeaderID != MAP_HEADER_RESORT_AREA && location->mapHeaderID != MAP_HEADER_VILLA) {
         SystemFlag_ClearVillaVisitorInside(varsFlags);
         SystemFlag_ClearVillaVisitorOutside(varsFlags);
         InitVillaVisitor(varsFlags, CalcVillaVisitorIndex(varsFlags));
diff --git a/src/tv_segment.c b/src/tv_segment.c
index 8e9b870543..5731b8d88d 100644
--- a/src/tv_segment.c
+++ b/src/tv_segment.c
@@ -7,6 +7,7 @@
 #include "constants/overworld_weather.h"
 #include "constants/tv_broadcast.h"
 #include "generated/first_arrival_to_zones.h"
+#include "generated/map_headers.h"
 #include "generated/natures.h"
 #include "generated/pokemon_stats.h"
 
@@ -341,7 +342,10 @@ typedef struct TVProgramType {
     const TVSegment *segments;
 } TVProgramType;
 
-#define TV_PROGRAM_SEGMENT_NULL { NULL, NULL }
+#define TV_PROGRAM_SEGMENT_NULL \
+    {                           \
+        NULL, NULL              \
+    }
 
 static const TVSegment sTrainerSightingsSegments[TV_PROGRAM_TYPE_TRAINER_SIGHTINGS_NUM_SEGMENTS];
 static const TVSegment sRecordsSegments[TV_PROGRAM_TYPE_RECORDS_NUM_SEGMENTS];
@@ -872,7 +876,7 @@ void FieldSystem_SaveTVSegment_HiddenItemBreakingNews(FieldSystem *fieldSystem,
     TVSegment_HiddenItemBreakingNews *hiddenItemBreakingNews = &segments.hiddenItemBreakingNews;
 
     hiddenItemBreakingNews->item = item;
-    hiddenItemBreakingNews->location = MapHeader_GetMapLabelTextID(fieldSystem->location->mapId);
+    hiddenItemBreakingNews->location = MapHeader_GetMapLabelTextID(fieldSystem->location->mapHeaderID);
 
     FieldSystem_SaveTVSegment(fieldSystem, TV_PROGRAM_TYPE_TRAINER_SIGHTINGS, TV_PROGRAM_SEGMENT_HIDDEN_ITEM_BREAKING_NEWS, hiddenItemBreakingNews);
 }
@@ -923,7 +927,7 @@ void FieldSystem_SaveTVSegment_HappyHappyEggClub(FieldSystem *fieldSystem, Pokem
     TVSegment_HappyHappyEggClub *happyHappyEggClub = &segments.happyHappyEggClub;
 
     TVSegment_CopyPokemonValues(mon, &happyHappyEggClub->species, &happyHappyEggClub->gender, &happyHappyEggClub->language, &happyHappyEggClub->metGame);
-    happyHappyEggClub->location = MapHeader_GetMapLabelTextID(fieldSystem->location->mapId);
+    happyHappyEggClub->location = MapHeader_GetMapLabelTextID(fieldSystem->location->mapHeaderID);
     FieldSystem_SaveTVSegment(fieldSystem, TV_PROGRAM_TYPE_TRAINER_SIGHTINGS, TV_PROGRAM_SEGMENT_HAPPY_HAPPY_EGG_CLUB, happyHappyEggClub);
 }
 
@@ -2166,64 +2170,64 @@ static BOOL FieldSystem_AlwaysTrue(FieldSystem *fieldSystem, TVEpisode *episode)
 static int TVSegment_LoadMessage_YourTownsBestThree(FieldSystem *fieldSystem, StringTemplate *template, TVEpisode *episode)
 {
     TrainerInfo *trainerInfo = SaveData_GetTrainerInfo(FieldSystem_GetSaveData(fieldSystem));
-    int mapID = fieldSystem->location->mapId;
+    enum MapHeaderID mapHeaderID = fieldSystem->location->mapHeaderID;
 
-    if (mapID == MAP_HEADER_TWINLEAF_TOWN || (mapID >= MAP_HEADER_TWINLEAF_TOWN_RIVAL_HOUSE_1F && mapID <= MAP_HEADER_TWINLEAF_TOWN_SOUTHWEST_HOUSE)) {
+    if (mapHeaderID == MAP_HEADER_TWINLEAF_TOWN || (mapHeaderID >= MAP_HEADER_TWINLEAF_TOWN_RIVAL_HOUSE_1F && mapHeaderID <= MAP_HEADER_TWINLEAF_TOWN_SOUTHWEST_HOUSE)) {
         StringTemplate_SetPlayerName(template, 0, trainerInfo);
         StringTemplate_SetRivalName(template, 1, fieldSystem->saveData);
         return TVProgramSinnohNow_Text_YourTownsBestThree_TwinleafTown;
     }
 
-    if (mapID == MAP_HEADER_SANDGEM_TOWN || (mapID >= MAP_HEADER_SANDGEM_TOWN_POKEMON_RESEARCH_LAB && mapID <= MAP_HEADER_SANDGEM_TOWN_HOUSE)) {
+    if (mapHeaderID == MAP_HEADER_SANDGEM_TOWN || (mapHeaderID >= MAP_HEADER_SANDGEM_TOWN_POKEMON_RESEARCH_LAB && mapHeaderID <= MAP_HEADER_SANDGEM_TOWN_HOUSE)) {
         StringTemplate_SetCounterpartName(template, 1, fieldSystem->saveData);
         return TVProgramSinnohNow_Text_YourTownsBestThree_SandgemTown;
     }
 
-    if (mapID == MAP_HEADER_FLOAROMA_TOWN || (mapID >= MAP_HEADER_FLOWER_SHOP && mapID <= MAP_HEADER_FLOAROMA_TOWN_MIDDLE_HOUSE) || mapID == MAP_HEADER_FLOAROMA_MEADOW_HOUSE) {
+    if (mapHeaderID == MAP_HEADER_FLOAROMA_TOWN || (mapHeaderID >= MAP_HEADER_FLOWER_SHOP && mapHeaderID <= MAP_HEADER_FLOAROMA_TOWN_MIDDLE_HOUSE) || mapHeaderID == MAP_HEADER_FLOAROMA_MEADOW_HOUSE) {
         return TVProgramSinnohNow_Text_YourTownsBestThree_FloaromaTown;
     }
 
-    if (mapID == MAP_HEADER_SOLACEON_TOWN || (mapID >= MAP_HEADER_POKEMON_DAY_CARE && mapID <= MAP_HEADER_SOLACEON_TOWN_EAST_HOUSE)) {
+    if (mapHeaderID == MAP_HEADER_SOLACEON_TOWN || (mapHeaderID >= MAP_HEADER_POKEMON_DAY_CARE && mapHeaderID <= MAP_HEADER_SOLACEON_TOWN_EAST_HOUSE)) {
         return TVProgramSinnohNow_Text_YourTownsBestThree_SolaceonTown;
     }
 
-    if (mapID == MAP_HEADER_CELESTIC_TOWN || (mapID >= MAP_HEADER_CELESTIC_TOWN_NORTH_HOUSE && mapID <= MAP_HEADER_CELESTIC_TOWN_CAVE)) {
+    if (mapHeaderID == MAP_HEADER_CELESTIC_TOWN || (mapHeaderID >= MAP_HEADER_CELESTIC_TOWN_NORTH_HOUSE && mapHeaderID <= MAP_HEADER_CELESTIC_TOWN_CAVE)) {
         return TVProgramSinnohNow_Text_YourTownsBestThree_CelesticTown;
     }
 
-    if (mapID == MAP_HEADER_JUBILIFE_CITY || (mapID >= MAP_HEADER_POKETCH_CO_1F && mapID <= MAP_HEADER_UNUSED_JUBILIFE_CITY_HOUSE_4)) {
+    if (mapHeaderID == MAP_HEADER_JUBILIFE_CITY || (mapHeaderID >= MAP_HEADER_POKETCH_CO_1F && mapHeaderID <= MAP_HEADER_UNUSED_JUBILIFE_CITY_HOUSE_4)) {
         return TVProgramSinnohNow_Text_YourTownsBestThree_JubilifeCity;
     }
 
-    if (mapID == MAP_HEADER_CANALAVE_CITY || (mapID >= MAP_HEADER_CANALAVE_LIBRARY_1F && mapID <= MAP_HEADER_CANALAVE_CITY_SAILOR_ELDRITCH_HOUSE) || mapID == MAP_HEADER_CANALAVE_CITY_WEST_HOUSE) {
+    if (mapHeaderID == MAP_HEADER_CANALAVE_CITY || (mapHeaderID >= MAP_HEADER_CANALAVE_LIBRARY_1F && mapHeaderID <= MAP_HEADER_CANALAVE_CITY_SAILOR_ELDRITCH_HOUSE) || mapHeaderID == MAP_HEADER_CANALAVE_CITY_WEST_HOUSE) {
         return TVProgramSinnohNow_Text_YourTownsBestThree_CanalaveCity;
     }
 
-    if (mapID == MAP_HEADER_OREBURGH_CITY || (mapID >= MAP_HEADER_OREBURGH_CITY_NORTHWEST_HOUSE_1F && mapID <= MAP_HEADER_OREBURGH_CITY_SOUTH_HOUSE)) {
+    if (mapHeaderID == MAP_HEADER_OREBURGH_CITY || (mapHeaderID >= MAP_HEADER_OREBURGH_CITY_NORTHWEST_HOUSE_1F && mapHeaderID <= MAP_HEADER_OREBURGH_CITY_SOUTH_HOUSE)) {
         return TVProgramSinnohNow_Text_YourTownsBestThree_OreburghCity;
     }
 
-    if (mapID == MAP_HEADER_ETERNA_CITY || (mapID >= MAP_HEADER_CYCLE_SHOP && mapID <= MAP_HEADER_UNUSED_ETERNA_CITY_HOUSE)) {
+    if (mapHeaderID == MAP_HEADER_ETERNA_CITY || (mapHeaderID >= MAP_HEADER_CYCLE_SHOP && mapHeaderID <= MAP_HEADER_UNUSED_ETERNA_CITY_HOUSE)) {
         return TVProgramSinnohNow_Text_YourTownsBestThree_EternaCity;
     }
 
-    if (mapID == MAP_HEADER_HEARTHOME_CITY || (mapID >= MAP_HEADER_HEARTHOME_CITY_SOUTHEAST_HOUSE_1F && mapID <= MAP_HEADER_FOREIGN_BUILDING)) {
+    if (mapHeaderID == MAP_HEADER_HEARTHOME_CITY || (mapHeaderID >= MAP_HEADER_HEARTHOME_CITY_SOUTHEAST_HOUSE_1F && mapHeaderID <= MAP_HEADER_FOREIGN_BUILDING)) {
         return TVProgramSinnohNow_Text_YourTownsBestThree_HearthomeCity;
     }
 
-    if (mapID == MAP_HEADER_PASTORIA_CITY || (mapID >= MAP_HEADER_PASTORIA_CITY_OBSERVATORY_GATE_1F && mapID <= MAP_HEADER_PASTORIA_CITY_NORTHEAST_HOUSE)) {
+    if (mapHeaderID == MAP_HEADER_PASTORIA_CITY || (mapHeaderID >= MAP_HEADER_PASTORIA_CITY_OBSERVATORY_GATE_1F && mapHeaderID <= MAP_HEADER_PASTORIA_CITY_NORTHEAST_HOUSE)) {
         return TVProgramSinnohNow_Text_YourTownsBestThree_PastoriaCity;
     }
 
-    if (mapID == MAP_HEADER_VEILSTONE_CITY || (mapID >= MAP_HEADER_GAME_CORNER && mapID <= MAP_HEADER_ROUTE_215_GATE_TO_VEILSTONE_CITY) || (mapID >= MAP_HEADER_GALACTIC_HQ_1F && mapID <= MAP_HEADER_GALACTIC_HQ_B2F)) {
+    if (mapHeaderID == MAP_HEADER_VEILSTONE_CITY || (mapHeaderID >= MAP_HEADER_GAME_CORNER && mapHeaderID <= MAP_HEADER_ROUTE_215_GATE_TO_VEILSTONE_CITY) || (mapHeaderID >= MAP_HEADER_GALACTIC_HQ_1F && mapHeaderID <= MAP_HEADER_GALACTIC_HQ_B2F)) {
         return TVProgramSinnohNow_Text_YourTownsBestThree_VeilstoneCity;
     }
 
-    if (mapID == MAP_HEADER_SUNYSHORE_CITY || (mapID >= MAP_HEADER_SUNYSHORE_MARKET && mapID <= MAP_HEADER_VISTA_LIGHTHOUSE) || mapID == MAP_HEADER_VISTA_LIGHTHOUSE_ELEVATOR) {
+    if (mapHeaderID == MAP_HEADER_SUNYSHORE_CITY || (mapHeaderID >= MAP_HEADER_SUNYSHORE_MARKET && mapHeaderID <= MAP_HEADER_VISTA_LIGHTHOUSE) || mapHeaderID == MAP_HEADER_VISTA_LIGHTHOUSE_ELEVATOR) {
         return TVProgramSinnohNow_Text_YourTownsBestThree_SunyshoreCity;
     }
 
-    if (mapID == MAP_HEADER_SNOWPOINT_CITY || (mapID >= MAP_HEADER_SNOWPOINT_CITY_WEST_HOUSE && mapID <= MAP_HEADER_SNOWPOINT_CITY_EAST_HOUSE)) {
+    if (mapHeaderID == MAP_HEADER_SNOWPOINT_CITY || (mapHeaderID >= MAP_HEADER_SNOWPOINT_CITY_WEST_HOUSE && mapHeaderID <= MAP_HEADER_SNOWPOINT_CITY_EAST_HOUSE)) {
         return TVProgramSinnohNow_Text_YourTownsBestThree_SnowpointCity;
     }
 
diff --git a/src/underground/secret_bases.c b/src/underground/secret_bases.c
index c7863541ae..b0e47b1967 100644
--- a/src/underground/secret_bases.c
+++ b/src/underground/secret_bases.c
@@ -229,7 +229,7 @@ typedef struct BaseTransitionContext {
     SysTask *sysTask;
     int state;
     int subState;
-    int mapID;
+    enum MapHeaderID mapHeaderID;
     int warpID;
     int x;
     int z;
@@ -1019,7 +1019,7 @@ static void SecretBases_StartExitBasePromptTask(FieldSystem *fieldSystem, int x,
     ctx->z = z;
     ctx->netID = netID;
     ctx->baseOwnerNetID = baseOwnerNetID;
-    ctx->mapID = MAP_HEADER_UNDERGROUND;
+    ctx->mapHeaderID = MAP_HEADER_UNDERGROUND;
     ctx->dir = dir;
     ctx->fieldSystem = fieldSystem;
     ctx->sysTask = SysTask_Start(SecretBases_ExitBasePromptTask, ctx, 100);
@@ -1042,9 +1042,9 @@ static BaseTransitionContext *BaseTransitionContext_New(FieldSystem *fieldSystem
         ctx->netID = netID;
         ctx->baseOwnerNetID = baseOwnerNetID;
 
-        GF_ASSERT(fieldSystem->location->mapId == MAP_HEADER_UNDERGROUND);
+        GF_ASSERT(fieldSystem->location->mapHeaderID == MAP_HEADER_UNDERGROUND);
 
-        ctx->mapID = MAP_HEADER_UNDERGROUND;
+        ctx->mapHeaderID = MAP_HEADER_UNDERGROUND;
         ctx->dir = dir;
     }
 
@@ -1248,7 +1248,7 @@ static void SecretBases_StartEnterBasePromptTask(FieldSystem *fieldSystem, int x
     ctx->z = z;
     ctx->netID = netID;
     ctx->baseOwnerNetID = baseOwnerNetID;
-    ctx->mapID = MAP_HEADER_UNDERGROUND;
+    ctx->mapHeaderID = MAP_HEADER_UNDERGROUND;
     ctx->dir = dir;
     ctx->fieldSystem = fieldSystem;
     ctx->timer = 0;
@@ -1651,7 +1651,7 @@ static BOOL SecretBases_MoveToFromSecretBaseTask(FieldTask *task)
         break;
     case MOVE_STATE_UPDATE_LOCATION:
         Location nextLocation;
-        nextLocation.mapId = ctx->mapID;
+        nextLocation.mapHeaderID = ctx->mapHeaderID;
         nextLocation.warpId = ctx->warpID;
         nextLocation.x = ctx->x;
         nextLocation.z = ctx->z;
diff --git a/src/unk_0203D1B8.c b/src/unk_0203D1B8.c
index a6d37fc6ee..93a7133f6e 100644
--- a/src/unk_0203D1B8.c
+++ b/src/unk_0203D1B8.c
@@ -1478,7 +1478,7 @@ void FieldSystem_HatchEgg(FieldSystem *fieldSystem)
     args.mon = eggMon;
     args.options = SaveData_GetOptions(fieldSystem->saveData);
     args.trainerInfo = SaveData_GetTrainerInfo(fieldSystem->saveData);
-    args.bgmID = FieldBGM_GetEffective(fieldSystem, fieldSystem->location->mapId);
+    args.bgmID = FieldBGM_GetEffective(fieldSystem, fieldSystem->location->mapHeaderID);
 
     EggHatch_HatchEgg(fieldSystem->task, &args);
 }
diff --git a/src/unk_02049D08.c b/src/unk_02049D08.c
index 6866757e14..8c2843ea4f 100644
--- a/src/unk_02049D08.c
+++ b/src/unk_02049D08.c
@@ -227,7 +227,7 @@ void BattleTower_SetCommunicationClubAccessible(FieldSystem *fieldSystem)
 {
     Location *v0 = FieldOverworldState_GetSpecialLocation(SaveData_GetFieldOverworldState(fieldSystem->saveData));
 
-    Location_Set(v0, fieldSystem->location->mapId, -1, PlayerAvatar_GetXPos(fieldSystem->playerAvatar), PlayerAvatar_GetZPos(fieldSystem->playerAvatar), 0);
+    Location_Set(v0, fieldSystem->location->mapHeaderID, -1, PlayerAvatar_GetXPos(fieldSystem->playerAvatar), PlayerAvatar_GetZPos(fieldSystem->playerAvatar), 0);
     SystemFlag_SetCommunicationClubAccessible(SaveData_GetVarsFlags(fieldSystem->saveData));
 
     return;
diff --git a/src/unk_020528D0.c b/src/unk_020528D0.c
index effb5e817a..c47dea1d54 100644
--- a/src/unk_020528D0.c
+++ b/src/unk_020528D0.c
@@ -11,6 +11,7 @@
 #include "brightness_controller.h"
 #include "field_bgm.h"
 #include "field_map_change.h"
+#include "field_map_change_flags.h"
 #include "field_overworld_state.h"
 #include "field_system.h"
 #include "field_task.h"
@@ -33,7 +34,6 @@
 #include "string_template.h"
 #include "system.h"
 #include "text.h"
-#include "unk_02070428.h"
 
 typedef struct {
     int unk_00;
@@ -121,7 +121,7 @@ static void sub_02052914(FieldSystem *fieldSystem, FieldTask *task)
     Window_AddFromTemplate(v0->unk_08, &v0->unk_0C, &Unk_020EC2F0);
     StringTemplate_SetPlayerName(v0->unk_20, 0, SaveData_GetTrainerInfo(FieldSystem_GetSaveData(fieldSystem)));
 
-    if (fieldSystem->location->mapId == MAP_HEADER_TWINLEAF_TOWN_PLAYER_HOUSE_1F) {
+    if (fieldSystem->location->mapHeaderID == MAP_HEADER_TWINLEAF_TOWN_PLAYER_HOUSE_1F) {
         sub_02052AA4(v0, 4, 0, 0);
     } else {
         sub_02052AA4(v0, 3, 0, 0);
diff --git a/src/unk_02056B30.c b/src/unk_02056B30.c
index 9d38f75f76..d402a8cef0 100644
--- a/src/unk_02056B30.c
+++ b/src/unk_02056B30.c
@@ -154,8 +154,6 @@ void sub_02056BDC(FieldSystem *fieldSystem, const int param1, const int param2,
 
 void sub_02056C18(FieldSystem *fieldSystem, const int param1, const int param2, const int param3, const int param4, const int param5)
 {
-    int v0;
-    int v1;
     UnkStruct_02056BDC *v2 = Heap_AllocAtEnd(HEAP_ID_FIELD2, sizeof(UnkStruct_02056BDC));
 
     v2->unk_00 = 0;
@@ -163,10 +161,10 @@ void sub_02056C18(FieldSystem *fieldSystem, const int param1, const int param2,
 
     Location_Set(&v2->unk_08, param1, param2, param3, param4, param5);
 
-    v0 = fieldSystem->location->mapId;
-    v1 = 0;
+    enum MapHeaderID mapHeaderID = fieldSystem->location->mapHeaderID;
+    int v1 = 0;
 
-    if (MapHeader_IsCave(v0)) {
+    if (MapHeader_IsCave(mapHeaderID)) {
         if (MapHeader_IsCave(param1)) {
             v1 = 6;
         } else if (MapHeader_IsOutdoors(param1)) {
@@ -176,7 +174,7 @@ void sub_02056C18(FieldSystem *fieldSystem, const int param1, const int param2,
         } else {
             GF_ASSERT(FALSE);
         }
-    } else if (MapHeader_IsOutdoors(v0)) {
+    } else if (MapHeader_IsOutdoors(mapHeaderID)) {
         if (MapHeader_IsCave(param1)) {
             v1 = 4;
         } else if (MapHeader_IsBuilding(param1)) {
@@ -184,7 +182,7 @@ void sub_02056C18(FieldSystem *fieldSystem, const int param1, const int param2,
         } else {
             GF_ASSERT(FALSE);
         }
-    } else if (MapHeader_IsBuilding(v0)) {
+    } else if (MapHeader_IsBuilding(mapHeaderID)) {
         if (MapHeader_IsOutdoors(param1)) {
             v1 = 0;
         } else if (MapHeader_IsBuilding(param1)) {
@@ -212,7 +210,7 @@ static BOOL sub_02056CFC(FieldTask *taskMan)
     switch (v1->unk_00) {
     case 0:
         v1->unk_04 = 0;
-        FieldBGM_TryFadeIn(fieldSystem, v2->mapId);
+        FieldBGM_TryFadeIn(fieldSystem, v2->mapHeaderID);
         FieldTask_InitCall(taskMan, Unk_020EC560[v1->unk_20], v1);
         (v1->unk_00)++;
         break;
@@ -240,7 +238,7 @@ static BOOL sub_02056CFC(FieldTask *taskMan)
             break;
         }
 
-        FieldBGM_PlayForMapHeader(fieldSystem, v2->mapId);
+        FieldBGM_PlayForMapHeader(fieldSystem, v2->mapHeaderID);
         FieldSystem_RequestLocationName(fieldSystem);
 
         v1->unk_04 = 0;
diff --git a/src/unk_02069BE0.c b/src/unk_02069BE0.c
index ba7b2b8b0c..d6f7547317 100644
--- a/src/unk_02069BE0.c
+++ b/src/unk_02069BE0.c
@@ -311,7 +311,7 @@ MapObject *sub_02069EB8(MapObject *mapObj)
 {
     int v0 = 0;
     int v1 = MapObject_GetTrainerType(mapObj);
-    int v2 = MapObject_GetMapID(mapObj);
+    enum MapHeaderID mapHeaderID = MapObject_GetMapHeaderID(mapObj);
     u32 v3 = MapObject_GetTrainerID(mapObj);
     const MapObjectManager *mapObjMan = MapObject_MapObjectManager(mapObj);
     MapObject *v5;
@@ -326,7 +326,7 @@ MapObject *sub_02069EB8(MapObject *mapObj)
     case 0x7:
     case 0x8:
         while (MapObjectMan_FindObjectWithStatus(mapObjMan, &v5, &v0, (1 << 0)) == 1) {
-            if ((mapObj != v5) && (MapObject_GetMapID(v5) == v2)) {
+            if ((mapObj != v5) && (MapObject_GetMapHeaderID(v5) == mapHeaderID)) {
                 if (MapObject_GetTrainerID(v5) == v3) {
                     return v5;
                 }
@@ -339,17 +339,18 @@ MapObject *sub_02069EB8(MapObject *mapObj)
 
 static int sub_02069F48(MapObject *mapObj, UnkStruct_02069F48 *param1)
 {
-    int v0, v1;
+    int v0;
+    enum MapHeaderID v1;
     u32 v2;
     MapObject *v3;
     const MapObjectManager *mapObjMan = MapObject_MapObjectManager(mapObj);
 
     v0 = 0;
-    v1 = MapObject_GetMapID(mapObj);
+    v1 = MapObject_GetMapHeaderID(mapObj);
     v2 = MapObject_GetTrainerID(mapObj);
 
     while (MapObjectMan_FindObjectWithStatus(mapObjMan, &v3, &v0, (1 << 0)) == 1) {
-        if ((mapObj != v3) && (MapObject_GetMapID(v3) == v1) && (MapObject_GetTrainerID(v3) == v2)) {
+        if ((mapObj != v3) && (MapObject_GetMapHeaderID(v3) == v1) && (MapObject_GetTrainerID(v3) == v2)) {
             if (param1->unk_01 == 0) {
                 sub_02069FC4(mapObj, param1, v3);
             }
diff --git a/src/unk_0206B9D8.c b/src/unk_0206B9D8.c
index 9946721f0f..6548d2034c 100644
--- a/src/unk_0206B9D8.c
+++ b/src/unk_0206B9D8.c
@@ -499,7 +499,7 @@ u32 sub_0206C068(SaveData *saveData)
 
 BOOL FieldSystem_IsInBattleTowerSalon(FieldSystem *fieldSystem)
 {
-    if (fieldSystem->location->mapId == MAP_HEADER_BATTLE_TOWER_BATTLE_SALON) {
+    if (fieldSystem->location->mapHeaderID == MAP_HEADER_BATTLE_TOWER_BATTLE_SALON) {
         return TRUE;
     }
 
diff --git a/src/unk_0208BA78.c b/src/unk_0208BA78.c
index dc0919c98a..cf3e0290bd 100644
--- a/src/unk_0208BA78.c
+++ b/src/unk_0208BA78.c
@@ -320,9 +320,9 @@ static BOOL sub_0208BC8C(UnkStruct_0208BC3C *param0, enum HeapID heapID)
             sub_02005464(0);
             Sound_SetScene(SOUND_SCENE_NONE);
 
-            bgmID = FieldBGM_GetEffective(param0->fieldSystem, param0->fieldSystem->location->mapId);
+            bgmID = FieldBGM_GetEffective(param0->fieldSystem, param0->fieldSystem->location->mapHeaderID);
 
-            Sound_SetFieldBGM(FieldBGM_GetForMapHeader(param0->fieldSystem, param0->fieldSystem->location->mapId));
+            Sound_SetFieldBGM(FieldBGM_GetForMapHeader(param0->fieldSystem, param0->fieldSystem->location->mapHeaderID));
             Sound_SetSceneAndPlayBGM(SOUND_SCENE_FIELD, bgmID, 1);
         }