Bayhorse Mine

Highlights
Precipitation runoff from Zortman and Landusky mines has deposited dangerous substances into nearby tributaries and rivers. A $13.8 million trust fund was set up to construct and operate three water capture and treatment systems. BLM helped secure a water treatment plant and wind turbine to offset power costs by $300,000 per year. The treatment plants the MT DEQ and BLM established have kept the water safe for local populations and wildlife.Federal Agency Landowner
Bureau of Land Management
Spanning some 1,200 cumulative acres, the Zortman and Landusky Mines are located two miles apart, in the Little Rocky Mountains of north-central Montana. Both mines are near the southern boundary of the Fort Belknap Indian Reservation in the southwest corner of Phillips County. The area’s gold mining activity stretches as far back as the late 1860s and continued up until 1998, when the mines’ most recent owner declared bankruptcy.
While restoration activities at these two sites were completed in the mid-2000s, precipitation runoff from both mines still flows into tributaries of the Milk and Missouri Rivers. Ongoing monitoring and maintenance activities include the maintenance of water capture and treatment systems that prevent excessive heavy metals, nitrates, selenium, and cyanide from being discharged into the surrounding streams. A $13.8 million water treatment trust fund was set up by the Montana Department of Environmental Quality (DEQ) to construct and operate three of these water capture and treatment systems. But in recent years, due to excessive precipitation in the area, water treatment costs have exceeded available funds by more than $1 million annually. This excessive precipitation also necessitated an additional water treatment system to treat waters flowing into the Swift Gulch, which flows onto the Fort Belknap Tribal Reservation.
With assistance from BLM in the spring of 2011, a water treatment plant for Swift Gulch was completed, along with a 225 kW wind turbine to help offset the approximately $300,000 in annual power costs such treatment plants require. While remediation efforts continue, the four treatment plants established by the MT DEQ and BLM have successfully prevented contaminants from being discharged into nearby streams and tributaries, keeping the water safe for local populations and wildlife.