Red Mountain Pass, Mountain pass in San Juan Mountains, Colorado.

Red Mountain Pass is a mountain pass in the San Juan Mountains of Colorado, located at 11,018 feet on U.S. Highway 550 connecting Ouray and Silverton. The route crosses through steep terrain with significant elevation changes across its length.

The Red Mountain Mining District, from the divide north to Ironton Park, saw a silver boom from 1882 to 1893, with mines such as the Yankee Girl and National Belle. Headframes of the old workings and the remains of Red Mountain Town, Ironton and Guston are still visible from the highway. The Idarado Mine kept digging until the 1970s, and reclamation of its tailings continues.

The pass takes its name from the Red Mountains, whose slopes are coloured by iron-oxide-laden rock. The Million Dollar Highway over the pass is part of the San Juan Skyway Scenic Byway. From the road, drivers can still see the headframes of old workings and the remains of Red Mountain Town, Ironton and Guston.

Winter driving here demands extra caution because of the steep grade combined with frequent avalanche risks and missing guardrails in many sections. Check road conditions before traveling and adjust your driving to match the terrain, especially during snow or rain.

The pass takes its name from the Red Mountains on its northeast side, whose slopes are colored by iron-oxide-laden rock. The German Wikipedia notes that these visible peaks are numbered from north to south. The divide also marks the boundary between the Uncompahgre and San Juan National Forests.