Million Dollar Highway, Colorado. The Million Dollar Highway is a scenic and thrilling 25-mile stretch of U.S. Route 550 in Colorado that runs between Ouray and Silverton, carved through the San Juan Mountains. Known for jaw-dropping views and a challenging drive, it features narrow, winding roads, steep drop-offs, and no guardrails in some areas. The route, part of the San Juan Skyway Scenic Byway, is famous for its dramatic mountain scenery, historic mining towns, and the high Red Mountain Pas