Atlantic Mine The Atlantic Mine structure is right along the road on the west side. Colorado State Highway 145 - Cortez to Placerville Part of the San Juan Skyway. Highway 145 runs from Cortez through the San Juan mountains to Telluride. Running out of Cortez through Dolores, along the Dolores River, over Lizard Head Pass, past Trout Lake, brushing Ophir, you approach awesome Telluride. Following the San Miguel River to Placerville, you meet route 62 that turns right to Ridgway. Follow this road for possibly the most beautiful mountain range in the country, the Sneffels Range.