Keith models the narrow-gauge Colorado & Southern as it existed between Breckenridge and Leadville, Colorado at the end of operations 1930-1940. Leadville was a mining town first prospected in the 1860s and later superseded in prominence by a large molybdenum mine located at Climax at the summit of Fremont Pass. The molybdenum mine grew considerably during the period modeled and is the main source of traffic. Trains will move from Denver staging across the to-be-constructed helix and up to Fremont Pass and Leadville.