Libby Dam, located on the Kootenai River near Libby, MT, is 422 feet tall and 3,055 feet long. Construction began in 1966 with 4 generators completed by 1975 and a fifth placed online in 1984 for a total capacity of 525 megawatts. The dam was built with 7.6 million tons of concrete and holds back the water of the Kootenai River forming Lake Koocanusa.