DEQ Press Releases

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Reclamation Nears Completion on Upper Blackfoot Mining Complex in Lewis & Clark County

HELENA—Reclamation work is nearing completion at the Upper Blackfoot Mining Complex (UBMC), a State Superfund site located in Lewis & Clark County east of Lincoln, Mont. 

The reclamation work has been a coordinated effort of the Department of Environmental Quality (DEQ), Department of Justice – Natural Resource Damage Program (NRDP) and United States Forest Service (Forest Service). 

Historical mining practices contaminated the floodplains and waterways downstream of the Mike Horse Dam. The dam was built in 1941 to contain mine tailings but failed in 1975, flushing more than 200,000 cubic yards of mine tailings downstream for almost 10 miles and into the Blackfoot River. Required restoration and reclamation work included removal of the tailings dam and contaminated floodplain waste, as well as stream channel construction and floodplain restoration.  

The cleanup removed approximately 1 million cubic yards of tailings and mine waste that had contaminated streams and the adjacent floodplains and made survival difficult for aquatic life, including fish. The contaminated material was removed from the banks and floodplain of the Blackfoot River and its tributaries, and encapsulated in a nearby repository. Water quality has returned to healthy levels following the reclamation and restoration of the site. 

“This site is a great example of agencies working together to clean up pollution left by historic mining,” said Project Officer Dave Bowers from DEQ. “This unique piece of Montana can now be used by everyone to enjoy the clean river, trails and wildlife. Most importantly, the site is protective of human health and the environment.” 

Restoration was completed on Mike Horse Creek, Beartrap Creek and Blackfoot River stream channels and adjacent floodplains.  Fish are already populating the newly constructed stream channels.

“Seeing the restored streams teeming with life as clean, cold water flows from high on the continental divide is something we can all be proud of,” said Restoration Project Manager Beau Downing from NRDP. “I believe I speak for everyone involved with the project in saying that the outcome has far exceeded our expectations. Working with DEQ, the USFS, our project partners, and the contractors to complete the project has been a highlight of my career.”

Funding for the cleanup came from a $39 million settlement with Atlantic Richfield Co. and ASARCO, LLC—companies that came to own much of the historic mining district.  

While a majority of the work is done, DEQ and the Forest Service may still have work to do in the areas outside the floodplains depending on the availability of alternative funding sources. Smaller areas disturbed by past exploration and mining practices were identified in the Record of Decision and need to undergo “design level” investigations. These investigations will determine the exact actions, if any, that need to be taken at each site. Depending on the outcomes of the investigations, possible actions could range from no action at all to complete removal. 

“The work completed at the site is a true demonstration of multiple agencies working cooperatively together for the betterment of the environment in Montana,” said Steve Opp, on-scene coordinator for the Helena-Lewis and Clark National Forest. “The project partners have committed to long-term monitoring of the site that will last several years to measure the effectiveness of the clean-up and restoration.” 

The site is now open for recreational use. The nonprofit Blackfoot Challenge is working on a self-guided tour that will feature information kiosks located throughout the UBMC. The kiosks will include information panels covering topics such as unique plants and wildlife as well as a history of the mining that occurred in the area.  

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