diff --git a/src/engine/InterestManagement/HeightMap.java b/src/engine/InterestManagement/HeightMap.java
index 09d7b83c..44de1097 100644
--- a/src/engine/InterestManagement/HeightMap.java
+++ b/src/engine/InterestManagement/HeightMap.java
@@ -229,16 +229,18 @@ public class HeightMap {
         // Interpolate height for this position using pixel array.
 
         float interpolatedTerrainHeight = heightMapZone.getHeightMap().getInterpolatedTerrainHeight(zoneLoc);
+        interpolatedTerrainHeight += heightMapZone.worldAltitude;
 
         // Heightmap blending is based on distance to edge of zone.
 
         if (Bounds.collide(worldLoc, heightMapZone.maxBlend) == true)
-            return interpolatedTerrainHeight + heightMapZone.worldAltitude;
+            return interpolatedTerrainHeight;
 
         // We will need the parent height if we got this far into the method
 
         parentZone = HeightMap.getNextZoneWithTerrain(heightMapZone.getParent());
         interpolatedParentTerrainHeight = HeightMap.getWorldHeight(parentZone, worldLoc);
+        interpolatedParentTerrainHeight += parentZone.worldAltitude;
 
         Bounds blendBounds = Bounds.borrow();
         zoneLoc.x = abs(zoneLoc.x);
@@ -262,9 +264,9 @@ public class HeightMap {
             percentage = currentDelta / blendDelta;
         else
             percentage = 0.0f;
-        float interpolatedWorldAltitude = FastMath.LERP(percentage, heightMapZone.worldAltitude, parentZone.worldAltitude);
+
         interpolatedTerrainHeight = FastMath.LERP(percentage, interpolatedTerrainHeight, interpolatedParentTerrainHeight);
-        return interpolatedTerrainHeight + interpolatedWorldAltitude;
+        return interpolatedTerrainHeight;
 
     }