LakeKoocanusa was created by the construction of Libby Dam. The lake is very large and stretches from within Canada down through part of Montana. It is 85 miles in length, but despite its enormous size, it does not receive much attention for either boating or fishing. WhitefishLake and FlatheadLake which lie close to LakeKoocanusa are the usual destinations for fishermen and boaters. During the late summer months, the water in LakeKoocanusa is drawn low for power production and this also limits boating activities.