The San Juan Skyway Scenic and Historic Byway is a 236-mile (380 km) All-American Road, National Forest Scenic Byway, and Colorado Scenic and Historic Byway located in Dolores, La Plata, Montezuma, San Juan, and San Miguel counties, Colorado, USA. The byway forms a loop in southwestern Colorado traversing the heart of the San Juan Mountains. The San Juan Skyway reaches its zenith at Red Mountain Pass at elevation 11,018 feet (3,358 m). Mesa Verde National Park was one of the original UNESCO World Heritage Sites. The Silverton Historic District and the Telluride Historic District are National Historic Landmarks.