Butte: The Richest Hill on Earth and What It Cost

The open pit that you can see from Interstate Fifteen north of Butte is the Berkeley Pit, one of the largest Superfund sites in the United States. It is a mile long and about half a mile wide, nearly eighteen hundred feet deep, and filled with about forty-five billion gallons of acidic, metal-laced water. It was a copper mine from nineteen fifty-five to nineteen eighty-two, when the Anaconda Company, which owned it, determined that mining was no longer profitable and pumped were turned off.

The groundwater began filling the pit immediately. In nineteen ninety-five, a flock of snow geese landed on the water during a November storm. Three hundred forty-two of them died within days.

The water pH is around two-point-five. The story of Butte is the story of copper, and before copper, silver and gold. The ore body under Butte Hill was discovered in the eighteen sixties and produced more wealth than almost any mineral deposit in American history.

At peak production in the early twentieth century, Butte was one of the largest cities between Minneapolis and Seattle, with a population some accounts put as high as one hundred thousand people, though the official census count was well under half that, underground mines that extended thousands of feet below the surface, and a labor movement that was among the most militant in the American West. The Anaconda Company eventually owned not just the mines but the newspapers, the politicians, and much of the political life of the state of Montana. Marcus Daly built his copper empire here.

William Clark, his rival, built his in competition. The Irish miners who came for the work built a community. The pit ate the community in the end, surface mining is cheaper than underground mining, and cheaper wins.

The water keeps rising. It will reach the groundwater table eventually. When it does, something happens that the environmental engineers prefer not to speculate about publicly.