Lake Koocanusa () is a reservoir in British Columbia ( Canada) and Montana ( United States) formed by the

dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, a ...

ming of the Kootenai River by the

Libby Dam Libby Dam is a concrete gravity dam in the northwestern United States, on the Kootenai River in northwestern Montana. Dedicated on it is west of the continental divide, upstream from the town of Libby. At in height and a length of , Libby Dam ...

in 1972. The Dam was formally dedicated by President Gerald Ford on August 24, 1975. Kootenai Bridge Over Lake Koocanusa

The lake is formed north of the dam, reaching to the

Canada–United States border The border between Canada and the United States is the longest international border in the world. The terrestrial boundary (including boundaries in the Great Lakes, Atlantic, and Pacific coasts) is long. The land border has two sections: Can ...

and further into British Columbia. The lake holds 13% of the water in the Columbia River system. The town of Rexford was moved, as well as the Great Northern Railway line. The town of Waldo, British Columbia is now covered by the lake. What was once a barrier to river travel, Jennings Canyon is now inundated by the lake. The Elk River joins the Kootenay River in the northern part of Lake Koocanusa, within Canadian territory. Lake Koocanusa was named in a contest won by Alice Beers of

Rexford, Montana Rexford is a town in Lincoln County, Montana, United States. The population was 78 at the 2020 census. The town began with the construction of the Great Northern Railway’s branch line from Jennings to Fernie, British Columbia in 1901. Rexfo ...

. The name is made from the first three letters of the Kootenay (alternately, Kootenai) River, Canada, and USA. Some confusion around the pronunciation of the lake exists and in an effort to acknowledge truth and reconciliation, locals have been urging people to pronounce the USA portion of the name the same way that you would pronounce the abbreviation. Lake Koocanusa was built as a joint project of the U.S. and Canada. It is 26 km (16 mi) from Libby, Montana, also on the Kootenai River, from which the dam gets its name.

has a Visitors Center and can be accessed by the Lake Koocanusa Scenic Byway which begins in the nearby town of

Libby Libby as a feminine given name is typically a diminutive form of Elizabeth, which is less commonly spelled 'Libbie' or ' Libi'. In recent years, it has been used as a shortened version of the name Liberty. As a surname, it can also be spelled ' ...

, Montana. The

Pacific Northwest National Scenic Trail The Pacific Northwest Trail (PNT) is a 1200-mile hiking trail running from the Continental Divide in Montana to the Pacific Ocean on Washington's Olympic Coast. Along the way, the PNT crosses three national parks, seven national forests, and t ...

follows Highway 37 along the east side of the lake before crossing over the Lake Koocanusa Bridge and climbing up Webb Mountain.

Selenium contamination

According to a March 8, 2021 article in '' The Narwhal'', concerns have been raised about selenium pollution leaching from

Teck Resources Teck Resources Limited, known as Teck Cominco until late 2008, is a diversified natural resources company headquartered in Vancouver, British Columbia, that is engaged in mining and mineral development, including coal for the steelmaking indu ...

' Elk Valley open pit coal mines' waste rock, which is upstream from the lake system. A September 24, 2020 Montana Department of Environmental Quality presentation to the Board of Environmental Review Meeting, reported that the 95% of the selenium coming into Lake Koocanusa originates from the Elk River—"which has been contaminated by current and historic coal mining in the Elk Valley." The average selenium levels in Lake Koocanusa were 1 part per billion. Montana has established new standards for selenium—0.8 parts per billion. Because of the high

bioaccumulation Bioaccumulation is the gradual accumulation of substances, such as pesticides or other chemicals, in an organism. Bioaccumulation occurs when an organism absorbs a substance at a rate faster than that at which the substance is lost or eliminated ...

of selenium in fish, excessive levels of selenium in an aquatic ecosystem has implications for human health. In the spring of 2020, Tech Resources, had "reported a dramatic decline in adult westslope

cutthroat trout The cutthroat trout is a fish species of the family Salmonidae native to cold-water tributaries of the Pacific Ocean, Rocky Mountains, and Great Basin in North America. As a member of the genus ''Oncorhynchus'', it is one of the Pacific trout ...

in Elk Valley waterways closest to its mines". Since 2015, British Columbia and Montana have agreed to adopt aligned standards for selenium levels by 2020. Montana's has been in force since the fall of 2020, but British Columbia has not aligned their standards yet.

Fish

The lake supports a wide variety of fish species. Below is a table detailing the various fish species which may be encountered on the lake.

References

External links

The Libby, Montana, web site
with more information about Lake Koocanusa

United States Army Corps of Engineers Bodies of water of Lincoln County, Montana Regional District of East Kootenay Reservoirs in British Columbia Reservoirs in Montana Lakes of British Columbia East Kootenay Canada–United States border International lakes of North America Kootenai National Forest Protected areas of Lincoln County, Montana Lakes of the Rocky Mountains Kootenay River Water pollution in the United States {{LincolnCountyMT-geo-stub