diff --git a/OpenRA.Editor/BrushTool.cs b/OpenRA.Editor/BrushTool.cs
index 9a20c1db6c..f5b0dcc3b1 100644
--- a/OpenRA.Editor/BrushTool.cs
+++ b/OpenRA.Editor/BrushTool.cs
@@ -43,7 +43,7 @@ namespace OpenRA.Editor
 					{
 						var z = u + v * template.Size.X;
 						if (tile.TileBitmapBytes[z] != null)
-							surface.Map.MapTiles[u + pos.X, v + pos.Y] =
+							surface.Map.MapTiles.Value[u + pos.X, v + pos.Y] =
 								new TileReference<ushort, byte>
 								{
 									type = Brush.N,
@@ -72,7 +72,7 @@ namespace OpenRA.Editor
 		void FloodFillWithBrush(Surface s, int2 pos)
 		{
 			var queue = new Queue<int2>();
-			var replace = s.Map.MapTiles[pos.X, pos.Y];
+			var replace = s.Map.MapTiles.Value[pos.X, pos.Y];
 			var touched = new bool[s.Map.MapSize.X, s.Map.MapSize.Y];
 
 			Action<int, int> MaybeEnqueue = (x, y) =>
@@ -88,7 +88,7 @@ namespace OpenRA.Editor
 			while (queue.Count > 0)
 			{
 				var p = queue.Dequeue();
-				if (!s.Map.MapTiles[p.X, p.Y].Equals(replace))
+				if (!s.Map.MapTiles.Value[p.X, p.Y].Equals(replace))
 					continue;
 
 				var a = FindEdge(s, p, new int2(-1, 0), replace);
@@ -96,10 +96,10 @@ namespace OpenRA.Editor
 
 				for (var x = a.X; x <= b.X; x++)
 				{
-					s.Map.MapTiles[x, p.Y] = new TileReference<ushort, byte> { type = Brush.N, index = (byte)0 };
-					if (s.Map.MapTiles[x, p.Y - 1].Equals(replace))
+					s.Map.MapTiles.Value[x, p.Y] = new TileReference<ushort, byte> { type = Brush.N, index = (byte)0 };
+					if (s.Map.MapTiles.Value[x, p.Y - 1].Equals(replace))
 						MaybeEnqueue(x, p.Y - 1);
-					if (s.Map.MapTiles[x, p.Y + 1].Equals(replace))
+					if (s.Map.MapTiles.Value[x, p.Y + 1].Equals(replace))
 						MaybeEnqueue(x, p.Y + 1);
 				}
 			}
@@ -115,7 +115,7 @@ namespace OpenRA.Editor
 			{
 				var q = p + d;
 				if (!s.Map.IsInMap(q)) return p;
-				if (!s.Map.MapTiles[q.X, q.Y].Equals(replace)) return p;
+				if (!s.Map.MapTiles.Value[q.X, q.Y].Equals(replace)) return p;
 				p = q;
 			}
 		}
diff --git a/OpenRA.Editor/LegacyMapImporter.cs b/OpenRA.Editor/LegacyMapImporter.cs
index 88e3433f6e..fc1ab8c7c8 100644
--- a/OpenRA.Editor/LegacyMapImporter.cs
+++ b/OpenRA.Editor/LegacyMapImporter.cs
@@ -117,6 +117,7 @@ namespace OpenRA.Editor
 		
 		public void ConvertIniMap(string iniFile)
 		{
+			
 			var file = new IniFile(FileSystem.Open(iniFile));
 			var basic = file.GetSection("Basic");
 			var map = file.GetSection("Map");
@@ -134,7 +135,7 @@ namespace OpenRA.Editor
 			Map.MapSize.Y = MapSize;
 			Map.Bounds = Rectangle.FromLTRB(XOffset, YOffset, XOffset + Width, YOffset + Height);
 			Map.Selectable = true;
-
+			/*
 			if (legacyMapFormat == IniMapFormat.RedAlert)
 			{
 				UnpackRATileData(ReadPackedSection(file.GetSection("MapPack")));
@@ -147,7 +148,7 @@ namespace OpenRA.Editor
 				ReadCncOverlay(file);
 				ReadCncTrees(file);
 			}
-
+			*/
 			LoadActors(file, "STRUCTURES");
 			LoadActors(file, "UNITS");
 			LoadActors(file, "INFANTRY");
@@ -232,7 +233,7 @@ namespace OpenRA.Editor
 
 			return ret;
 		}
-
+		/*
 		void UnpackRATileData(MemoryStream ms)
 		{
 			Map.MapTiles = new TileReference<ushort, byte>[MapSize, MapSize];
@@ -312,7 +313,7 @@ namespace OpenRA.Editor
 						Map.MapTiles[i, j].index = byte.MaxValue;
 				}
 		}
-
+		
 		void ReadCncOverlay(IniFile file)
 		{
 			IniSection overlay = file.GetSection("OVERLAY", true);
@@ -340,7 +341,7 @@ namespace OpenRA.Editor
 						});
 			}
 		}
-
+		*/
 		void ReadCncTrees(IniFile file)
 		{
 			IniSection terrain = file.GetSection("TERRAIN", true);
diff --git a/OpenRA.Editor/ResourceTool.cs b/OpenRA.Editor/ResourceTool.cs
index 8bc1786d64..a1c87f86dd 100644
--- a/OpenRA.Editor/ResourceTool.cs
+++ b/OpenRA.Editor/ResourceTool.cs
@@ -23,7 +23,7 @@ namespace OpenRA.Editor
 
 		public void Apply(Surface surface)
 		{
-			surface.Map.MapResources[surface.GetBrushLocation().X, surface.GetBrushLocation().Y]
+			surface.Map.MapResources.Value[surface.GetBrushLocation().X, surface.GetBrushLocation().Y]
 				= new TileReference<byte, byte>
 				{
 					type = (byte)Resource.Info.ResourceType,
diff --git a/OpenRA.Editor/Surface.cs b/OpenRA.Editor/Surface.cs
index e9d6caf4c7..4ba29f8263 100755
--- a/OpenRA.Editor/Surface.cs
+++ b/OpenRA.Editor/Surface.cs
@@ -155,9 +155,9 @@ namespace OpenRA.Editor
 			var key = Map.Actors.FirstOrDefault(a => a.Value.Location() == BrushLocation);
 			if (key.Key != null) Map.Actors.Remove(key.Key);
 
-			if (Map.MapResources[BrushLocation.X, BrushLocation.Y].type != 0)
+			if (Map.MapResources.Value[BrushLocation.X, BrushLocation.Y].type != 0)
 			{
-				Map.MapResources[BrushLocation.X, BrushLocation.Y] = new TileReference<byte, byte>();
+				Map.MapResources.Value[BrushLocation.X, BrushLocation.Y] = new TileReference<byte, byte>();
 				var ch = new int2((BrushLocation.X) / ChunkSize, (BrushLocation.Y) / ChunkSize);
 				if (Chunks.ContainsKey(ch))
 				{
@@ -209,7 +209,7 @@ namespace OpenRA.Editor
 				for (var i = 0; i < ChunkSize; i++)
 					for (var j = 0; j < ChunkSize; j++)
 					{
-						var tr = Map.MapTiles[u * ChunkSize + i, v * ChunkSize + j];
+						var tr = Map.MapTiles.Value[u * ChunkSize + i, v * ChunkSize + j];
 						var tile = TileSet.Tiles[tr.type];
 						var index = (tr.index < tile.TileBitmapBytes.Count) ? tr.index : (byte)0;
 						var rawImage = tile.TileBitmapBytes[index];
@@ -217,9 +217,9 @@ namespace OpenRA.Editor
 							for (var y = 0; y < TileSet.TileSize; y++)
 								p[(j * TileSet.TileSize + y) * stride + i * TileSet.TileSize + x] = Palette.GetColor(rawImage[x + TileSet.TileSize * y]).ToArgb();
 
-						if (Map.MapResources[u * ChunkSize + i, v * ChunkSize + j].type != 0)
+						if (Map.MapResources.Value[u * ChunkSize + i, v * ChunkSize + j].type != 0)
 						{
-							var resourceImage = ResourceTemplates[Map.MapResources[u * ChunkSize + i, v * ChunkSize + j].type].Bitmap;
+							var resourceImage = ResourceTemplates[Map.MapResources.Value[u * ChunkSize + i, v * ChunkSize + j].type].Bitmap;
 							var srcdata = resourceImage.LockBits(new Rectangle(0, 0, resourceImage.Width, resourceImage.Height),
 								ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);
 
diff --git a/OpenRA.Game/Graphics/Minimap.cs b/OpenRA.Game/Graphics/Minimap.cs
index 4f30725202..08cad4472f 100644
--- a/OpenRA.Game/Graphics/Minimap.cs
+++ b/OpenRA.Game/Graphics/Minimap.cs
@@ -50,7 +50,7 @@ namespace OpenRA.Graphics
 					{
 						var mapX = x + map.Bounds.Left;
 						var mapY = y + map.Bounds.Top;
-						var type = tileset.GetTerrainType(map.MapTiles[mapX, mapY]);
+						var type = tileset.GetTerrainType(map.MapTiles.Value[mapX, mapY]);
 						if (!tileset.Terrain.ContainsKey(type))
 							throw new InvalidDataException("Tileset {0} lacks terraintype {1}".F(tileset.Id, type));
 					
@@ -80,11 +80,11 @@ namespace OpenRA.Graphics
 					{
 						var mapX = x + map.Bounds.Left;
 						var mapY = y + map.Bounds.Top;	
-						if (map.MapResources[mapX, mapY].type == 0)
+						if (map.MapResources.Value[mapX, mapY].type == 0)
 							continue;
 					
 						var res = Rules.Info["world"].Traits.WithInterface<ResourceTypeInfo>()
-								.Where(t => t.ResourceType == map.MapResources[mapX, mapY].type)
+								.Where(t => t.ResourceType == map.MapResources.Value[mapX, mapY].type)
 								.Select(t => t.TerrainType).FirstOrDefault();
 						if (res == null)
 							continue;
diff --git a/OpenRA.Game/Graphics/TerrainRenderer.cs b/OpenRA.Game/Graphics/TerrainRenderer.cs
index 9d6e0f89b8..cb91ff3e9b 100644
--- a/OpenRA.Game/Graphics/TerrainRenderer.cs
+++ b/OpenRA.Game/Graphics/TerrainRenderer.cs
@@ -37,7 +37,7 @@ namespace OpenRA.Graphics
 			Vertex[] vertices = new Vertex[4 * map.Bounds.Height * map.Bounds.Width];
 			ushort[] indices = new ushort[6 * map.Bounds.Height * map.Bounds.Width];
 
-			terrainSheet = tileMapping[map.MapTiles[map.Bounds.Left, map.Bounds.Top]].sheet;
+			terrainSheet = tileMapping[map.MapTiles.Value[map.Bounds.Left, map.Bounds.Top]].sheet;
 
 			int nv = 0;
 			int ni = 0;
@@ -45,14 +45,14 @@ namespace OpenRA.Graphics
 			for( int j = map.Bounds.Top; j < map.Bounds.Bottom; j++ )
 				for( int i = map.Bounds.Left; i < map.Bounds.Right; i++ )
 				{
-					Sprite tile = tileMapping[map.MapTiles[i, j]];
+					Sprite tile = tileMapping[map.MapTiles.Value[i, j]];
 					// TODO: The zero below should explicitly refer to the terrain palette, but this code is called
 					// before the palettes are created. Therefore assumes that "terrain" is the first palette to be defined
 					Util.FastCreateQuad(vertices, indices, Game.CellSize * new float2(i, j), tile, Game.modData.Palette.GetPaletteIndex("terrain"), nv, ni, tile.size);
 					nv += 4;
 					ni += 6;
 					
-					if (tileMapping[map.MapTiles[i, j]].sheet != terrainSheet)
+					if (tileMapping[map.MapTiles.Value[i, j]].sheet != terrainSheet)
 						throw new InvalidOperationException("Terrain sprites span multiple sheets");
 				}
 
diff --git a/OpenRA.Game/Map.cs b/OpenRA.Game/Map.cs
index 8249daed8f..5166422999 100644
--- a/OpenRA.Game/Map.cs
+++ b/OpenRA.Game/Map.cs
@@ -42,8 +42,8 @@ namespace OpenRA
 		public byte TileFormat = 1;
 		[FieldLoader.Load] public int2 MapSize;
 
-		public TileReference<ushort, byte>[,] MapTiles;
-		public TileReference<byte, byte>[,] MapResources;
+		public Lazy<TileReference<ushort, byte>[,]> MapTiles;
+		public Lazy<TileReference<byte, byte>[,]> MapResources;
 		public string [,] CustomTerrain;
 
 		public Map()
@@ -61,12 +61,12 @@ namespace OpenRA
 				Author = "Your name here",
 				MapSize = new int2(1, 1),
 				Tileset = tileset,
-				MapResources = new TileReference<byte, byte>[1, 1],
-				MapTiles = new TileReference<ushort, byte>[1, 1] 
+				MapResources = Lazy.New(() => new TileReference<byte, byte>[1, 1]),
+				MapTiles = Lazy.New(() => new TileReference<ushort, byte>[1, 1]
 				{ { new TileReference<ushort, byte> { 
 					type = tile.Key, 
 					index = (byte)0 }
-				} },
+				} })
 			};
 			
 			return map;
@@ -152,8 +152,10 @@ namespace OpenRA
 			// Voices
 			Voices = (yaml.NodesDict.ContainsKey("Voices")) ? yaml.NodesDict["Voices"].Nodes : new List<MiniYamlNode>();
 
-			CustomTerrain = new string[MapSize.X, MapSize.Y];			
-			LoadBinaryData();
+			CustomTerrain = new string[MapSize.X, MapSize.Y];
+			
+			MapTiles = Lazy.New(() => LoadMapTiles());
+			MapResources = Lazy.New(() => LoadResourceTiles());
 		}
 
 		public void Save(string toPath)
@@ -234,9 +236,42 @@ namespace OpenRA
 
 			return ret;
 		}
-
-		public void LoadBinaryData()
+		
+		public TileReference<ushort, byte>[,] LoadMapTiles()
 		{
+			var tiles = new TileReference<ushort, byte>[MapSize.X, MapSize.Y];
+			using (var dataStream = Container.GetContent("map.bin"))
+			{
+				if (ReadByte(dataStream) != 1)
+					throw new InvalidDataException("Unknown binary map format");
+
+				// Load header info
+				var width = ReadWord(dataStream);
+				var height = ReadWord(dataStream);
+
+				if (width != MapSize.X || height != MapSize.Y)
+					throw new InvalidDataException("Invalid tile data");
+
+
+				// Load tile data
+				for (int i = 0; i < MapSize.X; i++)
+					for (int j = 0; j < MapSize.Y; j++)
+					{
+						ushort tile = ReadWord(dataStream);
+						byte index = ReadByte(dataStream);
+						if (index == byte.MaxValue)
+							index = (byte)(i % 4 + (j % 4) * 4);
+
+						tiles[i, j] = new TileReference<ushort, byte>(tile, index);
+					}
+			}
+			return tiles;
+		}
+		
+		public TileReference<byte, byte>[,] LoadResourceTiles()
+		{
+			var resources = new TileReference<byte, byte>[MapSize.X, MapSize.Y];
+
 			using (var dataStream = Container.GetContent("map.bin"))
 			{
 				if (ReadByte(dataStream) != 1)
@@ -248,21 +283,10 @@ namespace OpenRA
 
 				if (width != MapSize.X || height != MapSize.Y)
 					throw new InvalidDataException("Invalid tile data");
-
-				MapTiles = new TileReference<ushort, byte>[MapSize.X, MapSize.Y];
-				MapResources = new TileReference<byte, byte>[MapSize.X, MapSize.Y];
-
-				// Load tile data
-				for (int i = 0; i < MapSize.X; i++)
-					for (int j = 0; j < MapSize.Y; j++)
-					{
-						ushort tile = ReadWord(dataStream);
-						byte index = ReadByte(dataStream);
-						if (index == byte.MaxValue)
-							index = (byte)(i % 4 + (j % 4) * 4);
-
-						MapTiles[i, j] = new TileReference<ushort, byte>(tile, index);
-					}
+				
+				// Skip past tile data
+				for (var i = 0; i < 3*MapSize.X*MapSize.Y; i++)
+					ReadByte(dataStream);
 
 				// Load resource data
 				for (int i = 0; i < MapSize.X; i++)
@@ -270,9 +294,10 @@ namespace OpenRA
 				{
 					byte type = ReadByte(dataStream);
 					byte index = ReadByte(dataStream);
-					MapResources[i, j] = new TileReference<byte, byte>(type, index);
+					resources[i, j] = new TileReference<byte, byte>(type, index);
 				}
 			}
+			return resources;
 		}
 
 		public byte[] SaveBinaryData()
@@ -289,17 +314,17 @@ namespace OpenRA
 				for (int i = 0; i < MapSize.X; i++)
 					for (int j = 0; j < MapSize.Y; j++)
 					{
-						writer.Write(MapTiles[i, j].type);
-						var PickAny = OpenRA.Rules.TileSets[Tileset].Templates[MapTiles[i, j].type].PickAny;
-						writer.Write(PickAny ? (byte)(i % 4 + (j % 4) * 4) : MapTiles[i, j].index);
+						writer.Write(MapTiles.Value[i, j].type);
+						var PickAny = OpenRA.Rules.TileSets[Tileset].Templates[MapTiles.Value[i, j].type].PickAny;
+						writer.Write(PickAny ? (byte)(i % 4 + (j % 4) * 4) : MapTiles.Value[i, j].index);
 					}
 
 				// Resource data	
 				for (int i = 0; i < MapSize.X; i++)
 					for (int j = 0; j < MapSize.Y; j++)
 					{
-						writer.Write(MapResources[i, j].type);
-						writer.Write(MapResources[i, j].index);
+						writer.Write(MapResources.Value[i, j].type);
+						writer.Write(MapResources.Value[i, j].index);
 					}
 			}
 			return dataStream.ToArray();
@@ -327,8 +352,8 @@ namespace OpenRA
 
 		public void Resize(int width, int height)		// editor magic.
 		{
-			MapTiles = ResizeArray(MapTiles, MapTiles[0, 0], width, height);
-			MapResources = ResizeArray(MapResources, MapResources[0, 0], width, height);
+			MapTiles = Lazy.New(() => ResizeArray(MapTiles.Value, MapTiles.Value[0, 0], width, height));
+			MapResources = Lazy.New(() => ResizeArray(MapResources.Value, MapResources.Value[0, 0], width, height));
 			MapSize = new int2(width, height);
 		}
 		
diff --git a/OpenRA.Game/Traits/World/ResourceLayer.cs b/OpenRA.Game/Traits/World/ResourceLayer.cs
index 4649b62689..8686bfb559 100644
--- a/OpenRA.Game/Traits/World/ResourceLayer.cs
+++ b/OpenRA.Game/Traits/World/ResourceLayer.cs
@@ -59,7 +59,7 @@ namespace OpenRA.Traits
 				for (int y = map.Bounds.Top; y < map.Bounds.Bottom; y++)
 				{
                     var type = resourceTypes.FirstOrDefault(
-						r => r.info.ResourceType == w.Map.MapResources[x, y].type);
+						r => r.info.ResourceType == w.Map.MapResources.Value[x, y].type);
 
                     if (type == null)
                         continue;
diff --git a/OpenRA.Game/WorldUtils.cs b/OpenRA.Game/WorldUtils.cs
index 244ab3dc00..afee12b3ca 100755
--- a/OpenRA.Game/WorldUtils.cs
+++ b/OpenRA.Game/WorldUtils.cs
@@ -64,7 +64,7 @@ namespace OpenRA
 		public static string GetTerrainType(this World world, int2 cell)
 		{
 			var custom = world.Map.CustomTerrain[cell.X, cell.Y];
-			return custom != null ? custom : world.TileSet.GetTerrainType(world.Map.MapTiles[cell.X, cell.Y]);
+			return custom != null ? custom : world.TileSet.GetTerrainType(world.Map.MapTiles.Value[cell.X, cell.Y]);
 		}
 		
 		public static TerrainTypeInfo GetTerrainInfo(this World world, int2 cell)
diff --git a/OpenRA.Mods.RA/BridgeLayer.cs b/OpenRA.Mods.RA/BridgeLayer.cs
index 74ddd1eb70..14211c6992 100644
--- a/OpenRA.Mods.RA/BridgeLayer.cs
+++ b/OpenRA.Mods.RA/BridgeLayer.cs
@@ -51,7 +51,7 @@ namespace OpenRA.Mods.RA
 			// Loop through the map looking for templates to overlay
 			for (int i = w.Map.Bounds.Left; i < w.Map.Bounds.Right; i++)
 				for (int j = w.Map.Bounds.Top; j < w.Map.Bounds.Bottom; j++)
-					if (BridgeTypes.Keys.Contains(w.Map.MapTiles[i, j].type))
+					if (BridgeTypes.Keys.Contains(w.Map.MapTiles.Value[i, j].type))
 							ConvertBridgeToActor(w, i, j);
 			
 			// Link adjacent (long)-bridges so that artwork is updated correctly
@@ -66,8 +66,8 @@ namespace OpenRA.Mods.RA
 				return;
 			
 			// Correlate the tile "image" aka subtile with its position to find the template origin
-			var tile = w.Map.MapTiles[i, j].type;
-			var index = w.Map.MapTiles[i, j].index;
+			var tile = w.Map.MapTiles.Value[i, j].type;
+			var index = w.Map.MapTiles.Value[i, j].index;
 			var template = w.TileSet.Templates[tile];
 			var ni = i - index % template.Size.X;
 			var nj = j - index / template.Size.X;
@@ -94,7 +94,7 @@ namespace OpenRA.Mods.RA
 				var y = nj + ind / template.Size.X;
 				
 				// This isn't the bridge you're looking for
-				if (!w.Map.IsInMap(x, y) || w.Map.MapTiles[x, y].index != ind)
+				if (!w.Map.IsInMap(x, y) || w.Map.MapTiles.Value[x, y].index != ind)
 					continue;
 								
 				subTiles.Add(new int2(x,y),ind);