Superfund Site Profile

EPA is in the process of updating this site profile page with current information.  Until this update is complete, please contact the Remedial Project Manager, Dave Seter, at or at 415-972-3250 for site information.  Thank you for your patience.



The Rio Tinto Mine Site (Site) is a 280-acres abandoned copper mine located approximately 2.5 miles south of Mountain City, in northern Elko County, Nevada. The Site is located upstream of the Shoshone-Paiute Tribes’ Duck Valley Reservation on the East Fork Owyhee River. Mill Creek runs through the Site and flows into the East Fork Owyhee River. Both water bodies are impacted by mine-related heavy metals. This Site is designated as a Superfund Alternative Approach (SAA) site. Under this designation, EPA acts as support agency to the Nevada Division of Environmental Protection (NDEP, the lead agency).

The levels of copper, zinc, and cadmium in Mill Creek and the East Fork Owyhee River posed chronic and acute threats to aquatic life, including the redband trout, which is a species of cultural significance to the Shoshone-Paiute Tribes. The selected remedy required the excavation of more than 800,000 cubic yards of the tailings, with disposal in an on-site repository. Reconstruction of Mill Creek to facilitate fish movement through the area was also done. The construction was completed in November 2016.