Cumbres Pass, Rail mountain pass in San Juan Mountains, Colorado, US
Cumbres Pass is a mountain crossing in the San Juan Mountains at about 10,000 feet elevation, where both State Highway 17 and the Cumbres and Toltec Scenic Railroad run through. The terrain rises at roughly 4 percent from the south, while the steeper northern route approaches at about 5.8 percent.
The Denver & Rio Grande Railroad built the line through the pass in the 1880s as part of their San Juan Extension running from Alamosa to Durango. This route opened access to mining camps and remote settlements across challenging mountain terrain.
The site preserves structures tied to railroad operations, where workers once lived and managed the line from a mountain outpost. These buildings reflect how the railroad functioned as a small community at high elevation.
The pass remains open most of the year, though winter weather can make conditions unpredictable at this elevation. The southern approach offers a gentler grade and is often a better route during seasonal storms.
Extra helper locomotives were needed to assist trains in climbing the steep western slope from Chama, pushing them to the summit. This requirement reveals just how demanding the railroad's grades were.
The community of curious travelers
AroundUs brings together thousands of curated places, local tips, and hidden gems, enriched daily by 60,000 contributors worldwide.
