Lake Koocanusa, Montana

Lake Koocanusa is a 90-mile long body of water that was formed when the Kootenay River was dammed in 1972, a few miles to the west of the small and picturesque Montana town of Libby.

The main purpose of the 400-feet high Libby Dam on the Kootenai River was to provide flood protection and to generate hydroelectric power.

The dam is just over 40 miles to the south of Rexford – although half of the lake’s water is actually located in British Columbia, Canada.

The origin of the lake’s name is interesting in that it came about as the result of a contest held to come up with it. The winner apparently came up with Koocanusa by combining the first three letters of the Kootenay River with the first three letters of Canada and completing it by adding USA.

The reservoir is located on the traditional lands of the Ktunaxa, Ksanka, and Kootenai Peoples, and is an area of unsurpassed natural beauty surrounded by mountains.

You can find some outstanding wildlife watching opportunities at Lake Koocanusa, and the section of the lake in the U.S. is surrounded by the Kootenai National Forest.

The lake and its surrounding area offer a multitude of outdoor recreational opportunities including boating, fishing, lakeside camping, and picnicking.

The 67-mile Lake Koocanusa Scenic Byway, a federally designated National Forest Scenic Byway, runs between Eureka and Libby.

The drive winds its way around the vicinity of Lake Koocanusa’s eastern shoreline and includes impressive views that feature the Whitefish Range from the Tobacco Valley, as well as sweeping vistas of the lake and the surrounding mountains of the Purcell and Salish Ranges.

Highway 37 meets the far shore of the lake a few miles beyond Rexford and continues for another 40 miles or so to the dam, where the most scenic stretch of the lake lies. The Koocanusa Bridge is also close to this section of the drive.

This is the longest and highest bridge in Montana at almost 2,500 feet long, and it towers 270 feet above Lake Koocanusa, where some amazing views and photographic opportunities can be had.

lake koocanusa bridge

Lake Koocanusa Stats

  • Approximately 29,000 acres
  • 90-mile-long lake
  • 4 primitive campgrounds
  • Open year-round

Main Attractions

Aside from the multitude of outdoor recreation activities around the lake, one of the main attractions of the area is taking a tour of Libby Dam.

The interpretive and informative tours are available during the summer months, and feature exhibits and displays related to the dam’s role in flood control, hydroelectric power production, natural resources management, and recreation.

The visitor center is at the top of the dam on the west side of Forest Road 228, and serves as a focal point for the tours. There is also a day-use area adjacent to the center which features various amenities including restroom facilities, picnic tables, playgrounds, boat ramp access, and a disc golf course.

The visitor center, the dam, and the campgrounds and recreation areas are managed by the Army Corps of Engineers.

Things to do at Lake Koocanusa

The various recreation areas operated by the Corps at the dam and lake include primitive and boat access campgrounds. Several dispersed recreation sites are downstream from the dam including Alexander Creek, Dunn Creek Flats, and Blackwell Terrace. These sites allow boat access to the river, primitive camping, and excellent fishing.

There are nine Corps-managed public recreation areas that provide all the recreation opportunities you could wish for, and the U.S. Forest Service manages other additional recreation sites along the lake’s shores.

Fishing at Lake Koocanusa

The 370-feet deep Lake Koocanusa is open for year-round fishing, for which a Montana license is required. The best fishing is reportedly between mid-June and August when the water level is highest, and the lake is known to throw out a few large bull trout.

Smaller kokanee salmon and cutthroat trout are also prevalent, as are rainbow trout, brook trout, burbot, and whitefish.

Wildlife Viewing at Lake Koocanusa

The whole vicinity of Lake Koocanusa is teeming with wildlife – so much so that Libby Dam was designated as an ‘Official Watchable Wildlife Area’ by Montana Fish, Wildlife, and Parks in 1989. The area comprises the Downstream Natural Area and the David Thompson Bridge below the dam’s powerhouse.

Visitors have every chance of catching a glimpse or two of the odd deer, moose, and raccoon, as well as feathered species like bald eagles, geese, ducks, trumpeter swans, osprey, hawks, songbirds, and gulls.


On the Montana side of Lake Koocanusa, you will find various boating access points between Libby and Eureka. One of the main access points is the paved boat launch at Kikomun Creek Provincial Park.

If you have your own boat with you, consider recreation areas with boat ramps and lake access like Rocky Gorge, Peck Gulch, Barron Creek, and McGillivray Recreation Site.

The Marina on the lake offers rentals if necessary, and their range of boats includes pontoon boats, fishing boats, and jet skis.


If you just fancy a spot of paddling then the lake features hundreds of miles of accessible shoreline complete with sandy beaches, bays, and secluded coves. Boats of all sizes have their various uses in and around this lake.

Camping at Lake Koocanusa

There are four primitive campgrounds in the immediate vicinity of Lake Koocanusa and at least eight others of a more developed disposition, many of which are reservable.

The primitive camps are walk-in sites with no reservations and a 14-day maximum stay limit, namely:

Alexander Creek Camping Area is along the Forest Road to the west side of the river. It has two camping spots around 1.5 miles along the road, and you can identify the camping sites from a space next to a fire ring, a picnic table, and a garbage can. A primitive boat launch, parking, and a vault toilet are available here.

Blackwell Flats Campground is part of Lake Koocanusa and Libby Dam and has access to hiking and boating.

Downriver Camping Area has two sites right under the David Thompson Bridge, with another one just up from the boat launch near the wildlife ponds.  Again you can find the campsites by a metal fire-ring, picnic table, and garbage bin.

Dunn Creek Flats Campground is located 3 miles down from the dam on the eastern side of the river and has 13 sites. You’ll find a boat ramp, a launching dock, and day-use parking in this area.

You’ll also find a few more amenities here like a basketball hoop, a small campfire-talk amphitheater, and an old railroad grade connecting to the downstream launch area and wildlife ponds.

Rocky Gorge is one of the more developed and reservable grounds within the Lake Koocanusa vicinity. It has 120 campsites suitable for tents and RVs.

McGillivray Campground is 7.5 miles up from the dam on the west shore. It contains 50 camping units, picnic shelters, a swimming beach, restrooms, and a boat launching ramp.

This site comes with its own sandy beach swimming area, as well as a boat ramp to Lake Koocanusa, a Campground Host (seasonal), a day-use area, and flush toilet restrooms.

RVs up to 32′ can be accommodated, and firewood is available. McGillivray Campground has a stay limit of 14 days, and pets are allowed but must be kept on a leash.

A bit further across on the eastern shore you can find the Cripple Horse Campground, again around 7 miles above Libby Dam. Here you’ll get camping, a marina, boat launching, and picnicking facilities.

You can get from this recreation area to Yarnell Islands in just a short boat ride, and there you can make use of yet more camping and picnicking facilities.

Hiking Trails at Lake Koocanusa


When you consider that the Kootenai National Forest has more than 1,400 miles of trails, you know it won’t be too difficult to find one in the vicinity of the lake.

In fact, it’s possible to find some pretty remote hiking areas around the Cabinet Wilderness, and the Ten Lakes and Northwest Peaks Scenic Areas, not to mention the designated National Recreation Trails.

If you are looking for backwood trails with amazing views and sweeping vistas of Lake Koocanusa, you won’t find them lacking around here.

Eureka to Koocanusa

Many explorers opt for hiking between Eureka and Lake Koocanusa, along a trail that was once the old Tobacco River railroad grade. This route winds past various campgrounds and may include a few whitetails and mule deer along the way. Along with that, here are a couple of other ideas for decent hikes.

Alexander Mountain Trail

This is a 3.5-mile trail that runs just west of the dam and lake, starting out from Road 228 and finishing up at Fleetwood Point. The route includes elevations between around 2.5-4.5 thousand feet.

You get the picturesque overlooking views of the lake along this trail, especially at the half-mile point.

Hoodoo Loop Trail

The Hoodoo Loop Trail is a short half-mile loop on the Rexford wing of the dam.

This moderate-rated trail features views of the lake from a route used mainly for hiking, walking, and trail running, as well as observing nature.

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