Kootenay River

The Kootenay River is a major waterway in the North American Northwest Plateau.

It serves as one of the primary tributaries of the Columbia River. The Columbia is the largest river in North America that empties into the Pacific Ocean. The Kootenay is unique because it crosses the international border between Canada and the United States multiple times. It flows through southeastern British Columbia, northern Montana, and the northern Idaho Panhandle. The river is a vital part of the Columbia River system due to its large size.

The river's journey begins in the Kootenay Ranges of the Canadian Rockies. It is primarily fed by snowmelt and melting glaciers. From these high headwaters, the river flows through the East Kootenay region of British Columbia. It then moves south into northwestern Montana. The river turns west into the northernmost Idaho Panhandle. Finally, it returns to British Columbia to enter the West Kootenay region. There, it joins the Columbia River at the town of Castlegar. The river descends more than 2,000 feet from its start to its end.

Many different rivers join the Kootenay to increase its volume. The Duncan River is the largest tributary, stretching 140 miles long. Other important rivers include the Vermilion, the Elk, and the Yaak. The Elk River is the longest tributary of the Kootenay. In the middle section, the river flows through the Rocky Mountain Trench. This trench is a long, narrow strip of land. Scientists believe it is a graben, which is a piece of land that dropped down between faults.

The Ktunaxa people were the first inhabitants of the river valley. They lived along the river for hundreds of years to hunt and fish. They had different names for the river depending on where they lived. People living on the upper river called it aqkinmiluk, which simply means "river." Those on the lower river used the name aqkoktlaqatl. In the 19th century, the explorer David Thompson reached the river.

Thompson actually confused the Kootenay with the Columbia River at first. He named the real Kootenay "McGillivray's River" to honor his trading partners. Later, gold and silver strikes brought many miners and settlers to the region. This era brought railroads and steamboat navigation to the water.

The Kootenay River drains a massive watershed area. More than 70 percent of this area is located in Canada. Specifically, 23 percent is in Montana and 6 percent is in Idaho. The river is the third largest tributary of the Columbia by discharge and watershed size. One significant feature is Kootenay Lake, which is one of the largest natural lakes in British Columbia.

The river also forms Lake Koocanusa in Montana. This large reservoir was created by the Libby Dam. The river's path is shaped by hard, erosion-resistant rocks from the Belt Supergroup. These Precambrian sedimentary rocks form much of the surrounding mountains.

In the 20th century, the river's flow was changed by human engineering. Many dams were built to generate hydroelectricity. These dams also help protect the region from droughts and floods. For example, the Libby Dam in Montana creates Lake Koocanusa. Near the end of its journey, the river passes through deep canyons. This area features several waterfalls, such as Bonnington Falls. These falls are part of a system of four run-of-the-river hydroelectric dams.

Because of these dams, water levels in Kootenay Lake are now artificially regulated.

The Kootenay River connects many different geographic and cultural systems. It links the high Rocky Mountains to the larger Columbia River basin. The river's watershed is defined by parallel mountain ranges like the Selkirks and the Purcells. These mountains direct the water along a northwest to southeast axis. The river also connects different historical groups, from the Ktunaxa to the Russian Doukhobors. The Doukhobors established a colony called Brilliant near the mouth of the river. They eventually moved into many settlements and helped the local timber and farming industries. The river remains a central feature of the Pacific Northwest landscape.