The Berkeley Pit in Butte, Montana, has been a source of environmental concern for decades, as its waters—highly acidic and teeming with toxins—have seeped into the surrounding area. But today ...

The area surrounding the Berkeley Pit — a man-made lake of toxic water in Butte that would likely kill a human or animal that drank from it — is teeming with life.

HELENA, Mont. — Butte’s Berkeley Pit is infamously known for its toxicity, but it’s also the site of vital minerals and rare earth elements.

Kendall Cotton (Big Sky Voices, March 26) has got to be kidding when he argues that Montana should regain its place as the Treasure State by somehow resuming mining at the Berkeley Pit. He appears ...

The Berkeley Pit, however, has a much richer concentration of rare earths in solution and a higher volume of water and is expected to produce 40 tons a year. Dr. Ziemkiewicz believes this process ...