Use this map to make yours easily. Just extract the map, select the area you want and scale it to the size you want.
BE CAREFUL: when you are scaling the picture in GIMP; select Interpolation, None (fastest) then click Scale. In Photoshop this option is called Nearest Neighbor. If you don't do this the colors would be changed; and it is very difficult to restore them by hand.
Regards: LC.