Guston is a silver mining ghost town in Ouray County, Colorado, United States, 11 miles (18 km) south of Ouray following the "Million Dollar Highway". Nestled in Champion Gulch, it is located near Red Mountain and the remnants of Red Mountain Town and Ironton. The Silverton Railroad ran from Guston in the Red Mountain Pass to Silverton in San Juan County. The silver mining camp was established in 1883. The Guston post office operated from January 26, 1892, until November 16, 1898.