Lake Koocanusa () is a

reservoir A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation. Reservoirs can be created in a number of ways, including contro ...

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

(

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

) and

Montana Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columb ...

(

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

) 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 ...

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 c ...

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 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. Rexfor ...

. 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,

. The Pacific Northwest National Scenic Trail 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' 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 Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal (more rarely considered a metalloid) with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, ...

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 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 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 , colors = , anniversaries = 16 June (Organization Day) , battles = , battles_label = Wars , website = , commander1 = ...

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