The Castle Dome mining district is one of Yuma County's oldest and most productive mining locations. Its proximity to the Colorado River and relatively low rates of freight at the time permitted the mining of even low grades of ore which wouldn't have been profitable at other locations. In addition to silver and lead, the area is rich in numerous other minerals, including zinc, copper, gold, and many others. Total production from the Castle Dome mines included of lead, of silver, of zinc, of copper, of gold, and of placer gold production, mostly prior to 1900.
