Located in Chama, New Mexico, The Cumbres & Toltec Scenic Railroad was originally constructed in 1880 as part of the Rio Grande’s San Juan Extension, which served the silver mining district of the San Juan mountains in southwestern Colorado. Like all of the Rio Grande at the time, it was built to a gauge of 3 feet between the rails, instead of the more common 4 feet, 8-1/2 inches that became standard in the United States.