Marshall Pass atop the Continental Divide is one of the "great gates," as historian Marshall Sprague called the Rocky Mountain passes.  In the early 1880s, General William Jackson Palmer's Denver and Rio Grande raced Governor John Evans's Denver, South Park and Pacific to reach the booming Gunnison country, tap the mineral wealth of the San Juan Mountains, and attempt to become a transcontinental route.  Thanks to Marshall Pass, the Rio Grande won the race and for seven years was the only transcontinental line through Colorado.

Always a narrow gauge, Marshall Pass eventually lost its rails to the Rio Grande's standard gauge route over Tennessee Pass and the paved highway over Monarch Pass.  But with rigorous terrain, unforgiving locomotives, and a cast of colorful personalities from Otto Mears to postmaster Gus Latham, Marshall Pass remains at the center of Colorado's railroad heritage.