The Kootenay River or Kootenai River is a major river of the Northwest Plateau in southeastern British Columbia, Canada, and northern Montana and Idaho in the United States. It is one of the uppermost major tributaries of the Columbia River, the largest North American river that empties into the Pacific Ocean. The Kootenay River runs from its headwaters in the Kootenay Ranges of the Canadian Rockies, flowing from British Columbia's East Kootenay region into northwestern Montana, then west into the northernmost Idaho Panhandle and returning to British Columbia in the West Kootenay region, where it joins the Columbia at Castlegar.
The river is known as the "Kootenay" in Canada and by the Ktunaxa Nation, and as the "Kootenai" in the United States and by the Confederated Salish and Kootenai Tribes and Kootenai Tribe of Idaho. Fed mainly by glaciers and snowmelt, the river drains a rugged, sparsely populated region of more than , of which over 70 percent is in Canada. From its headwaters to its confluence with the Columbia River, the Kootenay descends more than . At their confluence, the Columbia and Kootenay are similar in length, drainage area, and volume, but less of the Kootenay is impounded in reservoirs and thus it has more free-flowing stretches with rapids and falls. Part of the lower Kootenay forms Kootenay Lake, one of the largest natural lakes in British Columbia.
The Ktunaxa (Kootenai) were the first people to live along the Kootenay River. For hundreds of years, they hunted and fished on the river, quite isolated from neighboring tribes. In the 19th century, Canadian explorer David Thompson became the first recorded European to reach the Kootenay and established trading posts throughout the region. A gold rush followed by silver and galena strikes in the late 19th century drew thousands of miners and settlers to the region, bringing developments such as railroads and steamboat navigation. The Doukhobors, a Russian religious sect, established a short-lived colony, Brilliant, at the Kootenay's mouth; subsequently dispersing into many settlements, they contributed to the region's timber and agricultural industries.
As with many Pacific Northwest rivers, many dams were built on the Kootenay in the 20th century to generate electricity and protect against floods and droughts. Water levels of Kootenay Lake are artificially regulated, and numerous hydroelectric dams block the river between Kootenay Lake and the Columbia River. Upstream of Kootenay Lake, most of the river is free-flowing with the exception of the Libby Dam in Montana, which forms Lake Koocanusa.
Name The river was described with slightly different names by two groups of the local Ktunaxa (Kootenai) Indian tribes. These indigenous people who lived along the upper river knew it as aqkinmiluk, simply meaning "river". The people along the lower river called it aqkoktlaqatl, a name whose meaning is not certain. The name "Flatbow River" comes from the name the Blackfeet used to call the Ktunaxa, for their "powerful, stylish bows",Jenish, p. 139 and was later recorded by French-Canadian fur traders.
While searching for the ultimate source of the Columbia River, explorer David Thompson encountered Columbia Lake, where the Columbia River starts north as a small stream and the Kootenay rushes south, already a powerful river. Already knowing from earlier maps that the region included two rivers called the Columbia and the Kootenay, Thompson thought that what is now called the Columbia was the Kootenay, and he thought that he had not yet found the real Kootenay. Thence he applied the name "McGillivray's River" to the real Kootenay in honor of his trading partners William and Duncan McGillivray.Jenish, p. 133 In his writings, the Columbia from Columbia Lake to the Big Bend was called the Kootenae.Burpee, p. lix
The name "Kootenai" was also used by French Canadians to refer to the Ktunaxa in the 19th century. "Kootenai" is thought to be a word meaning "water people" in an Algonquian language.Landers et al., p. 28 The river is still referred to as Kootenai in the United States, while in Canada it is spelled Kootenay.
Comparisons of various U.S. Geological Survey (USGS) topographic maps from the 20th century show many misinterpretations or alternative names being applied to the segment of the river within the United States. These include "Kootanie", "Kootenie", and "Kootienay". The Geographic Names Information System of the USGS lists "Swan River" as an alternate name, although the origin of this name is uncertain. (There is, however, a Swan River further southeast in Montana.)
Course
The Kootenay rises on the northeast side of the Beaverfoot Range of southeastern British Columbia and flows initially southeast through a marshy valley in Kootenay National Park. The river becomes significantly larger at its confluence with the Vermilion River, which is actually the larger of the two where they meet near Kootenay Crossing. The Kootenay continues southeast, receiving the Palliser River from the left, and flows south into a gorge at the confluence with the White River.
At the small town of Canal Flats the Kootenay River passes within of Columbia Lake, the headwaters of the Columbia River, as it merges into the Rocky Mountain Trench along the eastern foothills of the Purcell Mountains. It receives the Lussier River near Skookumchuck Station of the Canadian Pacific Railway and the St. Mary and Wild Horse rivers at the historic mining town of Fort Steele, then receives the Bull River at the settlement of the same name. At Wardner, British Columbia, the Kootenay widens into the Lake Koocanusa reservoir. The Elk River, the Kootenay's longest tributary, enters Lake Koocanusa south of Elko, British Columbia.
Stretching south and crossing the US-Canada Border, Lake Koocanusa is formed by Libby Dam east of Libby, Montana. The Kootenai (as it is now named) receives the Fisher River just downstream of the dam and turns west, forming the "Big Bend" around the southern end of the Purcell Mountains and Libby. About below Libby it drops over Kootenai Falls. The Kootenai turns northwest at Troy, Montana, before the Yaak River joins from the north as the river crosses into Idaho. The Moyie River enters near Moyie Springs before the river enters the gentle terrain of the Kootenai Valley and turns north, flowing past Bonners Ferry and back towards the US-Canada Border.
The river re-enters Canada south of Creston, British Columbia, and flows through a marshy area called the Kootenay Flats before emptying into the long Kootenay Lake. The lake is also joined by the Duncan River, the river's highest-volume tributary. Near Balfour an arm of the lake branches westward to Nelson, where the Kootenay River exits the lake below Corra Linn Dam. The final westbound stretch of the river flows through a deep canyon, forming several waterfalls including Bonnington Falls, where four run-of-the river hydroelectric dams impound the river. Near Brilliant the Kootenay forms a small inland delta then enters the Columbia River near Castlegar.
Watershed At , the Kootenay river's watershed is one of the largest sub-basins of the Columbia River system. The watershed stretches almost from north to south and from east to west, roughly defining a region of the Pacific Northwest known as the Kootenays.Kootenai Subbasin Plan Introduction, p. 11 In Canada, the term "Kootenays" is loosely defined although the Kootenay Land District, which includes the whole region, is formally defined; the name indirectly refers to the territory of the Kootenay indigenous people spanning from the Rockies on the east and the, Selkirks and Purcells (Percells in the U.S.) on the west in southeastern British Columbia (BC), and is used to mean more the area drained by the Kootenay River, namely including the lower Canadian stretches of the Columbia from Revelstoke to the US border, and also the reaches of the upper Columbia north from Canal Flats at least as far as Golden (the Boundary Country is sometimes referred to as being part of the West Kootenay).
The Kootenay is the third largest tributary of the Columbia by both watershed size and discharge.Tributaries section of Wikipedia article on Columbia River Over 70 percent of the Kootenay's watershed is in British Columbia, while 23 percent is in Montana and 6 percent is in Idaho. The Kootenay is one of only a few rivers that cross the US–Canada border multiple times: the others are the Milk River, a tributary of the Missouri River; the Souris River, a tributary of the Assiniboine River; and the Kettle River, a tributary of the Columbia River.
The Kootenay River watershed is defined by rugged parallel mountain ranges of the Rockies, which direct drainage along a northwest–southeast axis. The only large areas of flat land are in the Kootenay River valley from Bonners Ferry, Idaho to Kootenay Lake, and in parts of the Rocky Mountain Trench from Canal Flats to Lake Koocanusa. Of the Kootenay's many tributaries, the -long Duncan River is the largest. Hundreds of other tributaries join the river in its winding course, including the Vermilion, Cross, Palliser, White, Wild Horse, St. Mary, Elk, Fisher, Yaak, Moyie, Goat, and Slocan rivers.Kootenai Subbasin Plan Introduction, p. 12
Many river basins border the Kootenay—some are part of the Columbia Basin, while others drain to distant shores of the North American continent. On the south and southeast, the divide formed by the Cabinet and Whitefish ranges separate the Kootenay and Flathead River watersheds. The Flathead is a tributary of the Clark Fork River-Pend Oreille River system which borders the Kootenay watershed on the southwest. The upper Columbia River basin forms the boundary on the north, and the Kicking Horse River watershed also borders the north side of the Kootenay basin. To the southwest is the Priest River, a Pend Oreille tributary. On the east side, over the Continental Divide, the Bow River and Oldman River take rise. Both are tributaries of the South Saskatchewan River, which is part of the Hudson Bay drainage basin.
Geology
The geologic story of the Kootenay is strongly connected to the geology of the Columbia, Selkirk, and Rocky Mountains. The mountains in much of the Kootenay River catchment are composed of Precambrian sedimentary rock of the Belt Supergroup, in turn, stratified into several subgroups with slightly different characteristics and ages. However, most of the rocks have one thing in common; the rocks are generally hard and erosion-resistant.Kootenai Subbasin Plan Introduction, p. 26 The Rocky Mountain Trench is thought to be a partial graben, or a long narrow strip of land that has dropped in elevation over time because of parallel faults on both sides.Kootenai Subbasin Plan Introduction, p. 27 Faults in the Kootenay River watershed trend north-northwest to south-southeast as is common in much of British Columbia. The underlying rock is generally stable and contains more outcroppings of metamorphic and igneous rock as one progresses westwards.Kootenai Subbasin Plan Introduction, p. 28 Formations of Cambrian and Devonian rock also appear in small amounts in the U.S. portion of the Kootenay.