Denver and Rio Grande Western Railroad

The Denver and Rio Grande Western Railroad was built to serve the mining districts of Colorado and developed one of the most extensive narrow gauge railroad networks in the United States. The railroad later converted most main lines to standard gauge while retaining some narrow gauge branches.

The Rio Grande operated some of the most spectacular mountain railroad routes in North America, including the Royal Gorge, Tennessee Pass, and the Moffat Tunnel. The railroad's slogan "Through the Rockies, Not Around Them" captured its challenging operations across the Continental Divide.

The D&RGW was known for its distinctive orange and silver paint schemes and tough mountain operations requiring helper locomotives and careful train handling. The railroad's narrow gauge operations became tourist attractions, with portions still operating today as heritage railroads.

The Rio Grande merged with Southern Pacific in 1988 and was absorbed into Union Pacific in 1996. The Durango & Silverton and Cumbres & Toltec narrow gauge lines preserve the D&RGW narrow gauge heritage.