Sheep Creek is also unnecessary

by Bill Leith, Hamilton

 Why develop a new mine at Sheep Creek when there are economically retrievable, easily accessible concentrations of Rare Earth Elements ready for the taking in Butte?

A recent study by West Virginia University (WVU) estimated that the Berkeley Pit in Butte could produce as much as 50 tons per year of rare-earth element (REE) oxides, plus roughly 18 tons per year of cobalt.  In fact, REE-bearing sludge from the Berkeley Pit at Butte is already being shipped to West Virginia for concentration into usable rare earth minerals—a technology developed by WVU, based on assessments/assays by the Montana Bureau of Mines and Geology (MBMG). Further, a WV company, Mission Critical Minerals has been formed to commercialize the technology. 

The Berkeley Pit’s acid mine waste contains nearly ten times the concentration of REEs than other potential mine waste sources, such as the coal-mine drainage sources being studied in the same WVU program. Moreover, about 45% of the Pit’s REE waste contains heavy REEs— a bonus, because heavy REEs such as dysprosium, terbium and yttrium can be considerably more strategically valuable than the more abundant light REEs. MBMG’s data likewise show substantial concentrations of yttrium, dysprosium, erbium and other important REEs in the Berkeley Pit sludge. 

Now, the Montana Mining Association has submitted a funding proposal to the Department for a Montana Resources REE concentrator, and a November 2025 report said the Department of Defense was considering a $75 million grant to Montana Resources for construction of this concentrator (the status of this proposal is not evident).

My takeaway is that a perfect opportunity exists to develop a major, Montana-based industrial facility supporting the nation’s need for REEs.  Plus, establishing a production effort in Butte would dovetail nicely with efforts to clean up the Berkeley Pit superfund site.  Another bonus: its funding would obviously generate needed jobs in Butte.  

This proposal needs Montana Congressional support and Montana political advocacy.  Success securing the funding would be a major accomplishment and look good for any Montana politician.  

So forget Sheep Creek: establishing a production-scale process to extract REEs from Butte sludge would obviate the need to develop a mine at Sheep Creek, thus saving critical habitat, valuable water and pristine forest lands.