Miners came to Colorado for gold, stayed for silver, and survived after the 1890s by diversifying into a wide range of base and industrial metals such as lead, copper, zinc, molybdenum, tungsten, vanadium, radium, and uranium. Often ignored or discarded…

Located about two miles west of Nederland in western Boulder County, the Cardinal Mill processed gold, silver, and tungsten ore from its parent mine, the Boulder County Tunnel, as well as other local mines between 1902 and 1942. The Cardinal Mill was an…