 ARCO kept the plant open after Butte copper operations ceased in 1982, and sold the plant to a group of investors led by a former ARCO executive in 1985, due to high electricity costs and low market prices.As Columbia Falls Aluminum Company (CFAC), the plant continued operations as an independent company until it was purchased by Swiss metals giant Glencore AG in 1999.Glencore continued CFAC operations through 2009, when it temporarily shuttered the plant due to high electricity costs and low market prices.