Koocanusa was named in a contest won by Alice Beers of Rexford,
Montana. The name is made from the first three
letters of the Kootenay (alternately, Kootenai) River, Canada, and
USA. Lake Koocanusa was built as a joint project of the U.S. and
is 26 km (16 mi) from Libby, Montana, also on the Kootenai River, from which the dam
gets its name.