Libby Dam, Montana

The Libby Dam was completed in 1975, and flooded the Kootenai River valley forming a narrow lake 90 miles long, extending 42 miles into Canada. The name Koocanusa was invented for the man-made lake, and is a combination of Kootenai, Canada, and USA. The dam and reservoir is part of the Columbia River drainage, which is the most dammed major river system in the US. The 600 megawatts of electricity produced by the Libby Dam is managed by the Bonneville Power Administration, which provides electricity to cities as far away as Los Angeles.