The D&RG built this narrow-gauge line as the first part of its San Juan Extension to the rich mines of the San Juan Mountains. The 64-mile stretch between Antonito and Chama, which crosses the state border nine times, was restored as a summertime passenger excursion by the states of Colorado and New Mexico in 1971. A National Historic Civil Engineering Landmark, this serpentine line slithers along a granite shelf 1,000 feet above Toltec Gorge and climbs 10,015-foot-high Cumbres (Spanish, summit) Pass. It is the highest still-used passenger railroad in the United States. To cross some of the wildest and most remote terrain in Colorado, the D&RG used numerous cuts and fills, tunnels, and trestles and, as protection against snow, built on south-facing slopes and erected wooden snowsheds on Cumbres Pass.
Some of the water tanks, old depots, snow-sheds, and other structures along the line have been stabilized. The frame depot at Antonito (1971) is less distinguished than the rhyolite original ( CN07). The passenger coaches made in the Antonito shops during the 1980s loosely resemble their antique ancestors. Much original rolling stock and a typical railroad yard, including one of the few operational coaling towers in the country, may be found in Chama. In Antonito, Engine No. 463 (1903, Baldwin Locomotive Works, Philadelphia) (NR), restored by actor-singer Gene Autry, is a rare remnant of the Rio Grande's K-27 series, whose outside frame and Mikado wheel pattern allowed a much larger firebox. Coupled with a compound cylinder system that reused exhaust steam to power the drivers on the recovery stroke, this design doubled the tonnage a locomotive could pull over this route's 4 percent grades. A splendid guide to structures along the line, as well as the rolling stock, landscape, and history, is Doris B. Osterwald's Ticket to Toltec: A Mile by Mile Guide for the Cumbres & Toltec Scenic Railroad (1976).