diff --git a/data/uking_functions.csv b/data/uking_functions.csv
index f2bdc4a4..67a2f8fb 100644
--- a/data/uking_functions.csv
+++ b/data/uking_functions.csv
@@ -80407,7 +80407,7 @@ Address,Quality,Size,Name
 0x0000007100ee788c,U,000036,Actor::createDrops
 0x0000007100ee78b0,U,001192,eco::getEcosystemActorName
 0x0000007100ee7d58,U,000344,eco::sub_7100EE7D58
-0x0000007100ee7eb0,O,000056,_ZN4ksys3eco18currentAreaNumIs64ERKN4sead7Vector3IfEE
+0x0000007100ee7eb0,O,000056,_ZN4ksys3act22isInSatoriMountainAreaERKN4sead7Vector3IfEE
 0x0000007100ee7ee8,U,002112,
 0x0000007100ee8728,U,000388,
 0x0000007100ee88ac,U,000200,wm::isRainingOrSnowingOrThunderStorm
diff --git a/src/KingSystem/ActorSystem/actActorUtil.cpp b/src/KingSystem/ActorSystem/actActorUtil.cpp
index 75de3637..95062d8e 100644
--- a/src/KingSystem/ActorSystem/actActorUtil.cpp
+++ b/src/KingSystem/ActorSystem/actActorUtil.cpp
@@ -8,6 +8,7 @@
 #include "KingSystem/ActorSystem/actBaseProcLink.h"
 #include "KingSystem/ActorSystem/actInfoData.h"
 #include "KingSystem/ActorSystem/actTag.h"
+#include "KingSystem/Ecosystem/ecoSystem.h"
 #include "KingSystem/GameData/gdtManager.h"
 #include "KingSystem/Map/mapObject.h"
 #include "KingSystem/Map/mapPlacementMgr.h"
@@ -585,4 +586,8 @@ bool getSameGroupActorName(sead::SafeString* name, const sead::SafeString& actor
     return true;
 }
 
+bool isInSatoriMountainArea(const sead::Vector3f& pos) {
+    return eco::Ecosystem::instance()->getFieldMapArea(pos.x, pos.z) == 64;
+}
+
 }  // namespace ksys::act
diff --git a/src/KingSystem/ActorSystem/actActorUtil.h b/src/KingSystem/ActorSystem/actActorUtil.h
index cc642e99..e940f301 100644
--- a/src/KingSystem/ActorSystem/actActorUtil.h
+++ b/src/KingSystem/ActorSystem/actActorUtil.h
@@ -167,4 +167,6 @@ bool getSameGroupActorName(sead::SafeString* name, const sead::SafeString& actor
 
 s32 getSelectedChoiceIdx(s32 max, const char* query_name);
 
+bool isInSatoriMountainArea(const sead::Vector3f& pos);
+
 }  // namespace ksys::act
diff --git a/src/KingSystem/Ecosystem/CMakeLists.txt b/src/KingSystem/Ecosystem/CMakeLists.txt
index f45f7d24..5da05cec 100644
--- a/src/KingSystem/Ecosystem/CMakeLists.txt
+++ b/src/KingSystem/Ecosystem/CMakeLists.txt
@@ -3,6 +3,4 @@ target_sources(uking PRIVATE
   ecoLevelSensor.h
   ecoSystem.cpp
   ecoSystem.h
-  ecoUtil.cpp
-  ecoUtil.h
 )
diff --git a/src/KingSystem/Ecosystem/ecoUtil.cpp b/src/KingSystem/Ecosystem/ecoUtil.cpp
deleted file mode 100644
index 6ee2731e..00000000
--- a/src/KingSystem/Ecosystem/ecoUtil.cpp
+++ /dev/null
@@ -1,9 +0,0 @@
-#include "KingSystem/Ecosystem/ecoUtil.h"
-
-namespace ksys::eco {
-
-bool currentAreaNumIs64(const sead::Vector3f& pos) {
-    return Ecosystem::instance()->getFieldMapArea(pos.x, pos.z) == 64;
-}
-
-}  // namespace ksys::eco
diff --git a/src/KingSystem/Ecosystem/ecoUtil.h b/src/KingSystem/Ecosystem/ecoUtil.h
deleted file mode 100644
index 225e2de4..00000000
--- a/src/KingSystem/Ecosystem/ecoUtil.h
+++ /dev/null
@@ -1,10 +0,0 @@
-#pragma once
-
-#include <math/seadVector.h>
-#include "KingSystem/Ecosystem/ecoSystem.h"
-
-namespace ksys::eco {
-
-bool currentAreaNumIs64(const sead::Vector3f& pos);
-
-}  // namespace ksys::eco
diff --git a/src/KingSystem/World/worldTimeMgr.cpp b/src/KingSystem/World/worldTimeMgr.cpp
index 0deb6fb6..1c2b5a40 100644
--- a/src/KingSystem/World/worldTimeMgr.cpp
+++ b/src/KingSystem/World/worldTimeMgr.cpp
@@ -2,7 +2,7 @@
 #include <random/seadGlobalRandom.h>
 #include "KingSystem/ActorSystem/actActorConstDataAccess.h"
 #include "KingSystem/ActorSystem/actActorSystem.h"
-#include "KingSystem/Ecosystem/ecoUtil.h"
+#include "KingSystem/ActorSystem/actActorUtil.h"
 #include "KingSystem/Event/evtManager.h"
 #include "KingSystem/Event/evtMetadata.h"
 #include "KingSystem/GameData/gdtManager.h"
@@ -590,7 +590,7 @@ void TimeMgr::AnimalMasterController::calc() {
 
         if (!player_accessor.hasProc())
             break;
-        if (eco::currentAreaNumIs64(player_accessor.getPreviousPos()))
+        if (act::isInSatoriMountainArea(player_accessor.getPreviousPos()))
             break;
 
         appearance_hour = sead::GlobalRandom::instance()->getU32(23);
@@ -602,7 +602,7 @@ void TimeMgr::AnimalMasterController::calc() {
         if (!player_accessor.hasProc())
             break;
 
-        if (eco::currentAreaNumIs64(player_accessor.getPreviousPos())) {
+        if (act::isInSatoriMountainArea(player_accessor.getPreviousPos())) {
             state = 0;
             break;
         }