The Upper Blackfoot Mining Complex (UBMC) is located in the headwaters of the Blackfoot River in northwest Montana. Established in 1898, this historical mining site is a state superfund facility and has been an area of concern since hard rock mining operations ceased in the 1950’s. In 1975, a major flood breached the Mike Horse Tailings Impoundment and transported over 100,000 tons of contaminated mine tailings downstream into the Upper Blackfoot River. The dam breach altered the morphology of the valley and stream channel, resulting in geomorphic, water quality, and aquatic habitat impairments.
Restoration design criteria were developed from empirical, analog, and analytical methods, within the constraints of lateral and vertical boundary conditions set forth by remedial actions. UBMC’s delicate and complex biogeochemistry has posed a significant challenge in the effort to restore a healthy riparian corridor and stable fish-bearing, fluvial system. After four phases of remediation and restoration, over 870,000 cubic yards of contaminated mine waste have been removed, with two miles of channel and 20 acres of floodplain restored. Remedial and restoration actions are anticipated to be completed in 2019 ultimately restoring 3.3 miles and approximately 60 acres of the Blackfoot River and its tributaries.