Some ideas :

Maybe add two bridges? One at west and one at east. and then an island on the middle

Or maybe you can add more ships or kayaks to the game or maybe make the steamboat ridable and can help you ride to the north or to the south

Or maybe add some cars but those old looking cars that you saw in history books to make the more fun! ( Even tough it has nothing to do with the map .. )

Or at least make the steamboat visible ( i mention this on another post ) or else the steamboat is useless and have nothing to do with Ol'West....