Blue Ledge Mine is an abandoned hard-rock mine that operated from 1904 to 1930 on roughly 500 acres in the Rogue River-Siskiyou National Forest, about 3 miles south of the Oregon-California border in Siskiyou County, California. It was added to EPA's National Priorities List in September 2011. The mine includes more than 2 miles of underground tunnels, and acid mine drainage (AMD) from a single mine opening called adit-09 is the main source of contamination. The primary contaminants are copper, cadmium, and zinc. These metals reach Joe Creek at levels toxic to aquatic life. Copper in Joe Creek exceeds EPA's criterion continuous concentration, the threshold above which aquatic communities cannot survive long-term. No fish have been observed in the upper reaches of Joe Creek. Birds and mammals that eat fish from Joe Creek may also be harmed. Human health risks are limited overall. No cancer risks were identified. Drinking from acid mine runoff near the base of the mine could cause gastrointestinal distress. Eating fish from Applegate Reservoir may cause mercury-related health effects, and people should follow the Oregon Health Authority fish advisory. Swimming in Elliott Creek and the Applegate River is considered safe.
EPA has completed two major cleanup actions. In 2006, the agency reinforced a dam holding contaminated sediment, stabilized slopes, redirected mine water into a limestone treatment system, and built a sedimentation basin. From 2010 to 2011, the U.S. Forest Service removed about 66,521 cubic yards of waste rock from steep slopes using helicopters and hand scraping. These actions improved water quality, but additional cleanup is still needed to meet surface water goals.
The site is currently in the remedial investigation and feasibility study phase. EPA finalized its Remedial Investigation Report in January 2025. In spring 2025, EPA started a proof-of-concept treatability study testing passive treatment technology using limestone and steel slag pre-treatment beds paired with a sulfate-reducing biochemical reactor. A bench-scale study using 55-gallon drums is planned for spring 2026, with results expected in 2027. Land use restrictions recorded with Siskiyou County Recorder prevent residential development and other uses that could expose people to contaminated materials. Warning signs are posted along Joe Creek and mine entryways.
Community members can contact EPA's Community Involvement Coordinator or the Remedial Project Manager. For state-related questions, contact the California Department of Toxic Substances Control or the Oregon Department of Environmental Quality. There is no public information repository at the site, but key documents including the Remedial Investigation Report and Risk Assessments are part of the public record.
