How Big Is Great Slave Lake?

Bird's eye view of Great Slave Lake in the summertime.

5. Description

The fifth largest lake in North America, Great Slave Lake is located in the southern portion of the Northwest Territories province of Canada, near the border with Alberta. The lake is approximately 469 kilometers long, 203 kilometers wide, and has a maximum depth of 6,00 meters, making it the deepest lake in North America. The Great Slave Lake receives water from various rivers and streams, the largest one being the Slave River. The lake drains into the Mackenzie River to its west. The name of the lake is derived from the name of its indigenous human inhabitants, the Slavey people, a group of North American Indians.

4. Historical Role

Prior to the arrival of the European explorers into the region, the Great Slave Lake region was inhabited by indigenous Indian tribes like the Athapaskan tribes, with these including the Slavey Indians. With the development of the fur trade nearby, water routes in North America were extensively explored to facilitate the transport of fur along the waterways to the trade posts based at various points along such waterways. In 1771, British fur trader Samuel Hearne explored and crossed the frozen Great Slave Lake while he was returning from an expedition further north. In 1786, Fort Resolution, a fur trading post, was established along the lake’s southern shores by Laurent Leroux and Cuthbert Grant. Several fur trade posts owned by the Hudson Bay Company grew up along the shores of the Great Slave Lake, and the commercial trade in fur continued until it was replaced by gold mining in the early 20th Century. The incoming income from the flourishing gold exports allowed the town of Yellowknife along the lake to grow and develop at a rapid pace. Unfortunately, the lake was majorly impacted. On January 24th, 1978, when a Russian satellite carrying a nuclear reactor crashed on the lake and exploded, it ended up spilling out nuclear fuel into the lake's waters. A joint operation conducted by Americans and Canadians, known as the Operation Morning Star, was launched to clean up these nuclear pollutants from the lake.

3. Modern Significance

The Great Slave Lake is a famous tourist spot, offering recreational activities like camping, hiking, sport fishing, and ice fishing to its visitors. The lake also supports a commercial fishing industry, with trout and whitefish being the major catches from its waters. Hay River and Gros Cap are the most important fishing communities based along this river. In wintertime, goods and fuel are often transported across the frozen lake to the mineral exploration camps and diamond mines in the Great Slave Lake Basin area. Yellowknife, Fort Providence, and Fort Resolution are some of the major cities and towns based along the shores of this lake.

2. Habitat and Biodiversity

Large parts of the Great Slave Lake remain frozen for an average of eight months per year. The western shores of the lake support the growth of boreal forests, while tundra-like vegetation prevails on its northern and eastern shores. The East Arm of the lake, with an abundance of islands, is the site of the proposed Thaydene Nene National Park. The arctic grayling is an important aquatic inhabitant of the lake, and can survive under the lake’s thick ice sheet for months at a time. Northern pike, lake trout, and lake whitefish are some of the other notable fish species found in the waters of the lake. The Mackenzie Bison Sanctuary is located to the west side of the Great Slave Lake, and houses the world’s largest wood bison population. There, the Whooping Crane Summer Range to the south of the lake is famous for its nesting Whooping crane population.

1. Environmental Threats and Territorial Disputes

Though the Great Slave Lake is a vast reservoir of water, very little of it is deemed as being suitable for drinking. Residents of Yellowknife, residing on the northern shores of the river, will, instead of drinking the lake’s water, use water from the Yellowknife River which is 5 kilometers away. This is because the waters of the Great Slave Lake are believed to be laden with harmful quantities of mining wastes leached from the gold mines that once operated along the shores of the lake. The roasting process of extracting gold from arsenopyrite rocks, at least those carried out prior to 1999, generated vast quantities of highly toxic arsenic trioxide, which was stored in underground dumping sites a few hundred meters away from the shores of the lake. It is possible that this arsenic deposit continues to leach out into the waters of the lake, deeming it dangerous for human consumption. Currently, efforts are being made by the Canadian government to manage the toxic waste, and either freeze it in situ or remove it completely to then treat it as hazardous waste elsewhere.


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