diff --git a/include/ground_object.h b/include/ground_object.h
new file mode 100644
index 000000000..976f466ef
--- /dev/null
+++ b/include/ground_object.h
@@ -0,0 +1,27 @@
+#ifndef GUARD_GROUND_OBJECT_H
+#define GUARD_GROUND_OBJECT_H
+
+#include "structs/str_ground_script.h"
+
+void AllocGroundObjects(void);
+void DeleteGroundObjects(void);
+void FreeGroundObjects(void);
+void GroundObject_Select(s32 scriptID, s32 group, s32 sector);
+void GroundObject_Cancel(s32 scriptID, s32 sector);
+void GroundObject_CancelBlank(void);
+s32 GroundObject_Add(s32 id_, const GroundObjectData *objectData, s32 group_, s32 sector_);
+void sub_80AC1B0(s32 index_, s32 flag);
+Action *GroundObject_GetAction(s32 index_);
+bool8 GroundObject_GetScript(s32 index_, ScriptInfoSmall *scriptInfo, s32 a2_);
+bool8 GroundObject_ExecuteScript(s32 index_, ActionUnkIds *a1, ScriptInfoSmall *script);
+bool8 GroundObjectsNotifyAll(s32 index_);
+bool8 GroundObjectsCancelAll(void);
+s16 GroundObject_GetFlags(s32 index_, s32 *flags);
+s16 sub_80AC448(s32 index_, PixelPos *pos);
+s16 sub_80AC49C(s32 index_, PixelPos *pos);
+s32 sub_80AC4C8(s32 index, PixelPos *a0, PixelPos *a1);
+s32 sub_80AC554(s32 flag, PixelPos *param_2,PixelPos *param_3);
+void GroundObject_Action(void);
+void sub_80ACAD4(void);
+
+#endif // GUARD_GROUND_OBJECT_H
diff --git a/src/code_809D148.c b/src/code_809D148.c
index c8703c807..7c4fbcacf 100644
--- a/src/code_809D148.c
+++ b/src/code_809D148.c
@@ -8,6 +8,7 @@
 #include "ground_script.h"
 #include "ground_lives.h"
 #include "ground_effect.h"
+#include "ground_object.h"
 
 struct unkStruct_20399E8
 {
@@ -190,7 +191,6 @@ u8 sub_809D248(PixelPos *r0)
 }
 
 // Todo: move these to appropriate header files
-extern s32 sub_80AC448(s16 a0, PixelPos *a1);
 extern bool8 sub_80A579C(PixelPos *a0, PixelPos *a1);
 
 void sub_809D25C(void)
@@ -210,7 +210,7 @@ void sub_809D25C(void)
             gUnknown_20399E8.unk0 = 0;
         break;
     case 2:
-        val = sub_80AC448(gUnknown_20399E8.unk4, &gUnknown_20399E8.unk1C);
+        val = sub_80AC448((s16) gUnknown_20399E8.unk4, &gUnknown_20399E8.unk1C);
         if (val == (u16) -1)
             gUnknown_20399E8.unk0 = 0;
         break;
diff --git a/src/ground_lives.c b/src/ground_lives.c
index dadc8920b..720217325 100644
--- a/src/ground_lives.c
+++ b/src/ground_lives.c
@@ -18,6 +18,7 @@
 #include "friend_area_dialogue.h"
 #include "ground_lives_helper.h"
 #include "ground_sprite_monster.h"
+#include "ground_object.h"
 
 struct GroundLivesMeta_Sub1
 {
@@ -107,20 +108,14 @@ extern u8 sub_809D248(PixelPos *r0);
 extern s16 HandleAction(Action *action, const DebugLocation *debug);
 extern bool8 sub_80A66F8(struct UnkGroundSpriteStruct *ptr);
 extern bool8 sub_80A671C(struct UnkGroundSpriteStruct *ptr);
-extern s32 sub_80AC554(u32 a0, PixelPos *pixelPosArg1, PixelPos *pixelPosArg2);
-extern s32 sub_80AC448(s32 id_, PixelPos *pixelPos);
 extern bool8 sub_80A595C(u32 a0, PixelPos *pixelPosArg1, PixelPos *pixelPosArg2);
-extern void GroundObject_GetFlags(s32 id, s32 *a1);
 extern PixelPos SetVecFromDirectionSpeed(s32 r1, u32 r2);
 extern u8 sub_80A5934(s32 param_1, PixelPos *, PixelPos *);
 extern bool8 CheckMapCollision_80A585C(PixelPos *, PixelPos *);
 extern bool8 sub_80A58C8(PixelPos *, PixelPos *);
-extern s32 sub_80AC4C8(u32 a0, PixelPos *, PixelPos *);
 extern bool8 sub_809B1C0(s32 a0, u32 kind, Pokemon *a2);
 extern bool8 GetPredefinedScript(Action *param_1, ScriptInfoSmall *script, s32 _index);
 extern bool8 sub_809D678(Action *action);
-extern bool8 GroundObject_GetScript(s32 a0, ScriptInfoSmall *scriptInfo, s32 a2);
-extern void GroundObject_ExecuteScript(s32, void *, ScriptInfoSmall *);
 extern bool8 GroundScriptNotify(Action *param_1, s32 param_2);
 extern bool8 GroundScript_Cancel(Action *r0);
 extern Pokemon *sub_80A8D54(s32);
diff --git a/src/ground_main.c b/src/ground_main.c
index 3cace7b8b..011c1331b 100644
--- a/src/ground_main.c
+++ b/src/ground_main.c
@@ -28,6 +28,7 @@
 #include "ground_event.h"
 #include "ground_sprite.h"
 #include "ground_effect.h"
+#include "ground_object.h"
 
 EWRAM_DATA u32 gUnknown_20398A8 = {0};
 EWRAM_DATA s32 gUnknown_20398AC = {0};
@@ -73,7 +74,6 @@ extern bool8 sub_809AFAC(void);
 extern bool8 sub_80048BC(void);
 extern u8 sub_80023E4(u32);
 extern bool8 sub_8099B94(void);
-extern void FreeGroundObjects(void);
 extern void sub_809D508(void);
 extern void nullsub_119(void);
 extern void sub_8099768(void);
@@ -82,8 +82,6 @@ extern void sub_8099648(void);
 extern void sub_809975C(void);
 extern void sub_809D0AC(void);
 extern void sub_809D490(void);
-extern void AllocGroundObjects(void);
-extern void GroundObject_Action(void);
 extern void sub_809B474(void);
 extern void GroundScript_Unlock();
 extern void sub_809D25C(void);
@@ -98,7 +96,6 @@ extern void sub_80A5E70(void);
 extern void sub_809B638(void);
 extern void sub_8099750(void);
 extern void sub_809D0BC(void);
-extern void DeleteGroundObjects(void);
 extern void nullsub_16(void);
 extern void UpdateAdventureAchievements(void);
 extern void xxx_call_update_bg_sound_input(void);
diff --git a/src/ground_object.c b/src/ground_object.c
index ddca38a9f..047e6f5d4 100644
--- a/src/ground_object.c
+++ b/src/ground_object.c
@@ -1,5 +1,6 @@
 #include "global.h"
 #include "globaldata.h"
+#include "ground_object.h"
 #include "structs/str_ground_script.h"
 #include "debug.h"
 #include "data_script.h"
@@ -48,20 +49,24 @@ struct GroundObjectTypeData
 extern struct GroundObjectTypeData gGroundObjectTypes[];
 
 void DeleteGroundObjects(void);
-void GroundObject_Delete(s32);
 
 const struct GroundScriptHeader *GetGroundScript(s16 a0, DebugLocation *);
 void sub_80A7658(struct UnkGroundSpriteStruct *);
 extern bool8 GroundScriptNotify(Action*, s32);
 extern bool8 GroundScript_Cancel(Action *r0);
+extern bool8 GetPredefinedScript(Action *param_1, ScriptInfoSmall *script, s32 _index);
 void SetPredefinedScript(Action *param_1, s16 index, const ScriptCommand *param_3);
+extern bool8 sub_80A66F8(struct UnkGroundSpriteStruct *ptr);
+extern bool8 sub_80A671C(struct UnkGroundSpriteStruct *ptr);
+extern bool8 CheckMapCollision_80A585C(PixelPos *, PixelPos *);
+extern s16 HandleAction(Action *action, DebugLocation *debug);
+extern void sub_80A7664(struct UnkGroundSpriteStruct *ptr, PixelPos *pixelPos, s32 a2);
 
 extern bool8 GetCurrentDungeonBounds(PixelPos *a0, PixelPos *a1);
 void sub_80A75CC(void *, s32, s32, s32);
 
-
-s32 GroundObject_Add(s32 id_,const GroundObjectData *objectData,s32 group_,s32 sector_);
-
+static void GroundObject_Delete(s32 index_);
+static s32 TryMoveObjectRelative_80AC6AC(GroundObject *param_1, PixelPos *param_2);
 static s16 CallbackObjectGetIndex(void *ptr);
 static void CallbackObjectGetSize(void *objectPtr_, PixelPos *out);
 static void CallbackObjectSetHitboxPos(void *objectPtr_, PixelPos *posOrNull);
@@ -144,11 +149,6 @@ const u8 gGroundObjectFileName[];
 
 
 
-
-
-
-
-
 
 
 
@@ -170,7 +170,7 @@ static const struct ScriptCommand gUnknown_8118350[] = {
     JUMP_LABEL(0),
 };
 
-const s16 gUnknown_81183A0[] = {
+static const s16 gUnknown_81183A0[] = {
 -1,
 0x800,
 0x801,
@@ -198,15 +198,13 @@ const s16 gUnknown_81183A0[] = {
 
 void AllocGroundObjects(void)
 {
-
     GroundObject *ptr;
     s32 index;
 
     gGroundObjects = MemoryAlloc(sizeof(GroundObject) * NUM_GROUND_OBJECTS, 6);
 
-    for(index = 0,  ptr = &gGroundObjects[index]; index < NUM_GROUND_OBJECTS; index = (s16)(index + 1), ptr++)
-    {
-        ptr->kind |= -1;
+    for (index = 0,  ptr = &gGroundObjects[index]; index < NUM_GROUND_OBJECTS; index = (s16)(index + 1), ptr++) {
+        ptr->kind = -1;
     }
     DeleteGroundObjects();
 }
@@ -217,9 +215,8 @@ void DeleteGroundObjects(void)
     s32 index;
 
     ptr = &gGroundObjects[0];
-    for(index = 0; index < NUM_GROUND_OBJECTS; index = (s16)(index + 1), ptr++)
-    {
-        if(ptr->kind != -1)
+    for (index = 0; index < NUM_GROUND_OBJECTS; index = (s16)(index + 1), ptr++) {
+        if (ptr->kind != -1)
             GroundObject_Delete(index);
     }
 }
@@ -323,7 +320,7 @@ static s32 GroundObject_Find(s32 kind)
     return -1;
 }
 
-s32 GroundObject_Add(s32 id_,const GroundObjectData *objectData,s32 group_,s32 sector_)
+s32 GroundObject_Add(s32 id_, const GroundObjectData *objectData, s32 group_, s32 sector_)
 {
       s32 sVar3;
       s32 sVar4;
@@ -490,7 +487,7 @@ s32 GroundObject_Add(s32 id_,const GroundObjectData *objectData,s32 group_,s32 s
       return id;
 }
 
-void GroundObject_Delete(s32 index_)
+static void GroundObject_Delete(s32 index_)
 {
     s32 index = (s16)index_;
     GroundObject *parent = &gGroundObjects[index];
@@ -506,20 +503,18 @@ void sub_80AC1B0(s32 index_, s32 flag)
     s32 index = (s16)index_;
     GroundObject *parent = &gGroundObjects[index];
 
-    if(parent->kind != -1)
-    {
+    if (parent->kind != -1) {
         parent->flags |= flag;
         sub_80A6688(&parent->unk144, parent->flags);
     }
 }
 
-void sub_80AC1F4(s32 index_, s32 flag)
+static void sub_80AC1F4(s32 index_, s32 flag)
 {
     s32 index = (s16)index_;
     GroundObject *parent = &gGroundObjects[index];
 
-    if(parent->kind != -1)
-    {
+    if (parent->kind != -1) {
         parent->flags &= (0x337fffff ^ flag);
         sub_80A6688(&parent->unk144, parent->flags);
     }
@@ -530,15 +525,12 @@ Action *GroundObject_GetAction(s32 index_)
     s32 index = (s16)index_;
     GroundObject *parent = &gGroundObjects[index];
 
-    if(parent->kind != -1)
+    if (parent->kind != -1)
         return &parent->action;
     else
         return NULL;
 }
 
-extern bool8 GetPredefinedScript(Action *param_1, ScriptInfoSmall *script, s32 _index);
-
-
 bool8 GroundObject_GetScript(s32 index_, ScriptInfoSmall *scriptInfo, s32 a2_)
 {
     s32 index = (s16)index_;
@@ -551,7 +543,7 @@ bool8 GroundObject_GetScript(s32 index_, ScriptInfoSmall *scriptInfo, s32 a2_)
         return FALSE;
 }
 
-bool8 GroundObject_ExecuteScript(s32 index_, void *a1, ScriptInfoSmall *script)
+bool8 GroundObject_ExecuteScript(s32 index_, ActionUnkIds *a1, ScriptInfoSmall *script)
 {
     s32 index = (s16)index_;
     GroundObject *parent = &gGroundObjects[index];
@@ -649,9 +641,6 @@ s16 sub_80AC448(s32 index_, PixelPos *pos)
     return parent->kind;
 }
 
-extern s32 TryMoveObjectRelative_80AC6AC(GroundObject *, PixelPos *);
-
-
 s16 sub_80AC49C(s32 index_, PixelPos *pos)
 {
     s32 index = (s16)index_;
@@ -662,7 +651,8 @@ s16 sub_80AC49C(s32 index_, PixelPos *pos)
     return parent->kind;
 }
 
-s32 sub_80AC4C8(s32 index, PixelPos *a0, PixelPos *a1) {
+s32 sub_80AC4C8(s32 index, PixelPos *a0, PixelPos *a1)
+{
     GroundObject *parent = &gGroundObjects[0];
     s32 counter;
 
@@ -706,9 +696,7 @@ s32 sub_80AC554(s32 flag, PixelPos *param_2,PixelPos *param_3)
     return -1;
 }
 
-bool8 CheckMapCollision_80A585C(PixelPos *, PixelPos *);
-
-s32 GetObjectCollision_80AC5F4(GroundObject *param_1, PixelPos *param_2, PixelPos *param_3)
+static s32 GetObjectCollision_80AC5F4(GroundObject *param_1, PixelPos *param_2, PixelPos *param_3)
 {
     PixelPos local_28 = { param_2->x / 2048 , param_2->y / 2048 };
     PixelPos iVar1 = { (param_3->x - 1) / 2048, (param_3->y - 1) / 2048 };
@@ -725,7 +713,7 @@ s32 GetObjectCollision_80AC5F4(GroundObject *param_1, PixelPos *param_2, PixelPo
     return 0;
 }
 
-s32 TryMoveObjectRelative_80AC6AC(GroundObject *param_1,PixelPos *param_2)
+static s32 TryMoveObjectRelative_80AC6AC(GroundObject *param_1, PixelPos *param_2)
 {
     PixelPos local_1c;
     PixelPos local_14;
@@ -749,7 +737,7 @@ s32 TryMoveObjectRelative_80AC6AC(GroundObject *param_1,PixelPos *param_2)
     }
 }
 
-s32 TryMoveRelative_80AC720(GroundObject *param_1,PixelPos *param_2)
+static s32 TryMoveRelative_80AC720(GroundObject *param_1,PixelPos *param_2)
 {
     s32 ret;
     bool8 bVar1;
@@ -893,7 +881,8 @@ static void CallbackObjectSetDirection(void *livesPtr_, s32 direction)
     }
 }
 
-static void CallbackObjectSetEventIndex(void *livesPtr_, u16 a1) {
+static void CallbackObjectSetEventIndex(void *livesPtr_, u16 a1)
+{
     struct GroundObject *livesPtr = livesPtr_;
 
     u32 r1;
@@ -917,8 +906,8 @@ static void CallbackObjectSetEventIndex(void *livesPtr_, u16 a1) {
         livesPtr->directionRelated = 1;
 }
 
-
-static void CallbackObjectSetUnk_80AC998(void *objectPtr_, s32 a1_, s32 a2) {
+static void CallbackObjectSetUnk_80AC998(void *objectPtr_, s32 a1_, s32 a2)
+{
     struct GroundObject *livesPtr = objectPtr_;
 
     s32 a1Match = (s16) a1_;
@@ -935,9 +924,6 @@ static void CallbackObjectSetUnk_80AC998(void *objectPtr_, s32 a1_, s32 a2) {
     livesPtr->unk140 = a1;
 }
 
-extern bool8 sub_80A66F8(struct UnkGroundSpriteStruct *ptr);
-extern bool8 sub_80A671C(struct UnkGroundSpriteStruct *ptr);
-
 static bool8 CallbackObjectSpriteRelatedCheck_80AC9B8(void *objectPtr_)
 {
     struct GroundObject *livesPtr = objectPtr_;
@@ -990,8 +976,6 @@ static s32 CallbackObjectMoveRelative(void *livesPtr_, PixelPos *pos)
     return TryMoveRelative_80AC720(livesPtr, pos);
 }
 
-extern s16 HandleAction(Action *action, DebugLocation *debug);
-
 void GroundObject_Action(void)
 {
     GroundObject *objectPtr;
@@ -1020,8 +1004,6 @@ void GroundObject_Action(void)
     }
 }
 
-void sub_80A7664(struct UnkGroundSpriteStruct *ptr, PixelPos *pixelPos, s32 a2);
-
 void sub_80ACAD4(void)
 {
     GroundObject *objectPtr;
diff --git a/src/ground_script.c b/src/ground_script.c
index 432e61ba2..8e9099dde 100644
--- a/src/ground_script.c
+++ b/src/ground_script.c
@@ -52,16 +52,12 @@
 #include "textbox.h"
 #include "ground_event.h"
 #include "ground_effect.h"
+#include "ground_object.h"
 
 void GroundMap_Select(s16);
 void GroundMap_SelectDungeon(s32, DungeonLocation*, u32);
 void GroundMap_GetStationScript(ScriptInfoSmall *out, s16, s32, s32);
-void GroundObject_ExecuteScript(s32, ActionUnkIds *, ScriptInfoSmall *);
-void GroundObject_Select(s32, s32 group, s32 sector);
-void GroundObject_Cancel(s32 group, s32 sector);
-void GroundObject_CancelBlank(void);
 void GroundWeather_Select(s16);
-s16 GroundObject_Add(s16 id, GroundObjectData*, s16 group, s8 sector);
 
 // Beware of the declarations without specified arguments, returning u32 or s32, these were quickly hacked in to get the code to compile and link
 // The return values are almost certainly NOT correct and will need to be rechecked when moving to header files
@@ -90,9 +86,6 @@ void sub_809D1E4(s32, s32, s32);
 void sub_809D208(s32, PixelPos*, s32);
 void sub_809D220(s32, s32, s32);
 void GroundScriptLockJumpZero(s16);
-s16 sub_80AC448(s16, PixelPos*);
-s32 sub_80AC49C(s16, PixelPos*);
-void DeleteGroundObjects(void);
 s32 ExecuteScriptCommand(Action *action);
 bool8 sub_8099B94(void);
 PixelPos SetVecFromDirectionSpeed(s8, s32);
@@ -106,15 +99,11 @@ bool8 sub_809D234(void);
 s32 sub_80A14E8(Action *, u8, u32, s32);
 u8 sub_80990EC(struct DungeonSetupInfo *param_1, s32 param_2);
 
-extern u8 GroundObjectsCancelAll(void);
 extern u8 IsTextboxOpen_809A750(void);
-extern Action *GroundObject_GetAction(s32);
 extern void sub_809AB4C(s32, s32);
 extern void sub_809ABB4(s32, s32);
 extern void sub_809AC18(s32, s32);
 
-bool8 GroundObjectsNotifyAll(s16);
-
 void sub_8098C58(void);
 void sub_8098CC8(void);
 bool8 sub_80961D8(void);
@@ -127,7 +116,6 @@ u8 sub_80964E4();
 void sub_80A56A0(s32, s32);
 void sub_80A56F0(PixelPos *);
 void sub_80A5704(PixelPos *);
-void sub_80AC1B0(s16, s32);
 s32 sub_80A5984();
 void sub_80A59A0(s32, s32 *, u16);
 extern bool8 sub_80A579C(PixelPos *a0, PixelPos *a1);
diff --git a/src/ground_sprite.c b/src/ground_sprite.c
index fb35720a3..2cb580a3d 100644
--- a/src/ground_sprite.c
+++ b/src/ground_sprite.c
@@ -14,6 +14,7 @@
 #include "effect_sub_1.h"
 #include "pokemon.h"
 #include "ground_effect.h"
+#include "ground_object.h"
 
 static IWRAM_INIT unkStruct_3001B7C *gUnknown_3001B7C = {NULL};
 
@@ -31,7 +32,6 @@ static EWRAM_INIT OpenedFile *gUnknown_203B4B4 = {NULL};
 // code_8098BDC.s
 extern void sub_809971C(u16, const u8 *, s16);
 extern void sub_80997F4(u16, u16);
-extern void sub_80ACAD4(void);
 extern void sub_800E970(void);
 extern u8 sub_809D248(PixelPos *r0);