Lake Koocanusa, created by Libby Dam on the Kootenai River, is a 29,000 acre lake, stretching from Montana all the way back into Canada. Due to its isolated location in far northwest Montana, as well as the nearby proximity to Whitefish Lake and Flathead Lake, the lake only receives a fair amount of use for fishing and recreational boating.
Draw downs of the reservoir for power production in late summer during low water years can leave Lake Koocanusa very low—which can limit boat landing opportunities.
Lake Koocanusa has a wide variety of fish. Rainbow trout, brook trout, whitefish, kookanee salmon, cutthroat trout and bull trout all are found in the lake. The Montana FWP regularly stocks the lake with rainbow trout as well.
Additionally, bass, pike, pumpkinseed and yellow perch are also found in the lake.
Some limited shore fishing is possible in the spring and early summer, before the draw down, for small cutthroat trout and kokanee salmon. However, due to the lakes very large size, a motorboat is needed to reach the best fishing spots.
Access to Lake Koocanusa is quite good. Highway 37 parallels the lake on the east side for most of its distance. On the west side, a bumpy dirt road more or less parallels the lake too. A number of boat landings, some private and some public, are located on both sides of the lake and near Libby Dam.
Overall, Lake Koocanusa isn’t slated to be the next destination spot for Montana fly fishing, especially since the Kootenai River just below Libby Dam is such a fine fishery. However, the lake lies in a scenic setting and its relatively low use allows a person to find some solitude, making Lake Koocanusa a fine place to spend an early summer day.