The Big Stack: Black Eagle and the Anaconda Smelter

Across the river from Great Falls, in the neighborhood of Black Eagle, a chimney rose from the earth in nineteen oh eight that briefly stood taller than anything else built by human hands on the American continent. Five hundred and six feet of brick, with a base diameter of seventy-eight feet tapering to fifty at the top. When the Boston and Montana smelter completed it on October twenty-third, nineteen oh eight, it was the tallest chimney in the world.

The smelter itself had been running since eighteen ninety-one, processing copper ore from regional mines in a comprehensive metallurgical operation that eventually employed more than a thousand workers. The Boston and Montana company merged into the newly formed Amalgamated Copper Company around the turn of the century, which later became Anaconda Copper. The smelter and its enormous stack became the defining silhouette of this stretch of the Missouri for decades, visible from thirty miles away on clear days, the plume trailing east across the plains.

What the stack exhausted into the air, and what the operation poured into the river, accumulated over generations. Between eighteen ninety-two and nineteen fifteen, an estimated twenty-seven million to thirty-one million cubic yards of waste were discharged directly into the Missouri River. Arsenic, cadmium, and mercury contamination extended thirty-four miles downstream. The smelter closed in nineteen eighty. The Environmental Protection Agency designated the site a Superfund cleanup zone in two thousand eleven.

The Big Stack itself was demolished on September eighteenth, nineteen eighty-two. The neighborhood of Black Eagle remains, named as it was from the beginning for a black eagle that Lewis and Clark noted nesting in a cottonwood on an island in the river just below the first falls. The bird was here before the stack, and the name outlasted both.