Last weekend we decided to go up an ride the Georgetown Loop Railroad here in Colorado. Not a very long ride (4 miles total), but it has some nostalgic value because they still run a steam train. The highlight of the trip is the 100' high curved bridge at "Devil's Gate"
The route connects Georgetown to SilverPlume, two towns that are only about 1 mile apart but over 600' in elevation difference. So, a direct run would not work without running a cog train. More info on the rail line can be found here: http://www.georgetownlooprr.com/