Columbia Falls Aluminum Plant, Montana

The plant opened in 1955, built by the Anaconda Company, located here because of the power available from the Hungry Horse Dam, and grew over the following decade, until it could produce 180,000 tons of aluminum per year, in 1968. In 1977, Anaconda was purchased by ARCO, by which point the plant had almost 1,000 workers. ARCO sold the plant in 1985, and by 2001 it was struggling, and is idled for the first time. It closed for good in 2009, and the operation officially became a superfund clean up site in 2016.