The Upper Blackfoot Mining Complex project area is located in Lewis and Clark County, Montana, approximately 15 miles east of Lincoln, Montana at the headwaters of the Blackfoot River. Mining activities began in the Upper Blackfoot Mining Complex project area in the late 1800s and continued into the 1950s. The 1930s and 1940s were the most active mining periods with mining ceasing in the 1950s. In 1941, the Mike Horse Dam was constructed across Beartrap Creek creating the Mike Horse Tailings Impoundment where tailings from the Mike Horse Mine mill were disposed. In 1975 the Mike Horse Dam was breached during a spring storm event that produced heavy runoff that combined with rapid spring runoff. The breach released an estimated 100,000 tons of tailings and other materials into the UBMC project area below the dam.
The purpose of this restoration action is to restore self-sustaining ecological processes that will result in clean, connected habitat for westslope cutthroat trout, support downstream populations of bull trout and other important aquatic species, and maintain adjacent riparian and terrestrial habitat to support wildlife populations that depend on those habitats.