Alpine Tunnel is a 1,772 feet (540 m) narrow gauge railroadtunnel located east of Pitkin, Colorado on the former Denver, South Park and Pacific Railroad route fromDenver to Gunnison. At an elevation of 11,523 feet (3,512 m), it was the first tunnel constructed through the Colorado Continental Divide, and according to the U.S. Forest Service"remains the highest railroad tunnel and the longest narrow gauge tunnel in North America." However, it did not last long in service. Construction began in January 1880 and was scheduled to last for six months but instead dragged on till July 1882, and the line was abandoned in 1910 due to minor damage in the tunnel. Now the tunnel is sealed shut and the remaining trackbed serves as a trail for hikers and off-road vehicles. The Alpine Tunnel was "holed through" on July 26, 1881. Location of the tunnel portals and establishing a center line of the bore were completed in December 1879. Construction of the Alpine Tunnel took place between 1880–1881, by Cummings & Co. Construction company. This was the highest and most expensive tunnel built up until that time. It exceeds two miles (3 km) above sea level, with its highest point at 11,523.7 feet (3,512.4 m). It is 500 feet (150 m) under Altman Pass, later to be named Alpine Pass to prevent confusion, with a 1,825-foot (556 m) bore. It took 18 months to complete, with most of the construction done during the winter months. History It was abandoned in 1910 by the Colorado & Southern due to minor damage in the tunnel and it not being worth repairing with a lack of traffic as the line failed to get much further beyond Gunnison on the west side. The Gunnison Division of the Colorado & Southern was abandoned from St Elmo, Colorado on the east side of the pass to Quartz on the west site. The Line from Quartz Pitkin, Colorado to Baldwin was given to the Denver & Rio Grande Western in exchange for some little used lines around Leadville. - Wikipedia
