There are more than 1,500 properties and historic districts in the U.S. State of Colorado listed on the National Register of Historic Places. They are distributed over 63 of Colorado's 64 counties; only the City and County of Broomfield currently has none.

The Cumbres and Toltec Scenic Railroad, often abbreviated as the C&TSRR, is a 3 ft narrow-gauge heritage railroad that operates on 64 miles (103 km) of track between Antonito, Colorado, and Chama, New Mexico, in the United States. The railroad is named for two geographical features along the route: the 10,015-foot (3,053 m)-high Cumbres Pass and the Toltec Gorge. Originally part of the Denver and Rio Grande Western Railroad's narrow-gauge network, the line has been jointly owned by the states of Colorado and New Mexico since 1970. Today, the C&TSRR is one of only two remaining parts of the former D&RGW narrow-gauge network, the other being the Durango and Silverton Narrow Gauge Railroad (D&SNG), which runs between the communities of Durango and Silverton, Colorado. The railroad has a total of ten narrow-gauge steam locomotives and two narrow-gauge diesel locomotives on its current roster. The railroad also operates two smaller former D&RGW steam locomotives, Nos. 315 and 168, for special events and excursions.