Where are custom maps stored?
Custom maps, created using the terrain editor, are stored in your Preferences folder. To find them, follow these steps:
After creating and saving your map in Sid Meier's Railroads!, exit the game.
Relaunch the game by double-clicking on the Sid Meier's Railroads! Application icon while holding the Command (⌘) key. The Sid Meier's Railroads! pre-game Options window will appear.
Select the Advanced tab and click on the Open Preferences Folder button. A new finder window will open showing the Sid Meier's Railroads! folder contents on your computer’s hard drive.
Open the UserMaps folder to view a list of folders, each containing data for one of your saved custom maps.
To install maps created by other players, simply place them in the UserMaps folder.
NOTE: Since the terrain editor used to create these maps is an unsupported modding tool, you may experience strange behaviour or crashes when you play them.