What is Great Slave Lake?

Great Slave Lake is the deepest lake in North America at 614 metres and the fifth-largest lake in Canada by surface area at 28,568 square kilometres. The lake is in the southern Northwest Territories and straddles the boundary between the Canadian Shield (which forms the eastern shore) and the Interior Plains (which form the western shore). The lake's volume of about 1,580 cubic kilometres makes it the tenth-largest lake in the world by volume, similar to Lake Erie despite Erie being larger by surface area.

The lake's English name derives from the French Lac des Esclaves ('Lake of the Slaves'), a name applied by the French to the Dene peoples by their Cree neighbours, who called the Dene awahkan (slaves). The Dene call the lake Tu Nedhe ('Big Lake') in the Chipewyan dialect and Tucho in the Slavey dialect. The Akaitcho Treaty 8 Tribal Council and the Tlicho Government represent the principal Indigenous nations of the region. The Tlicho Land Claims and Self-Government Agreement of August 25, 2003 (effective August 4, 2005) was the first combined comprehensive land claim and self-government agreement in Canadian history.

The lake drains to the Arctic Ocean via the Mackenzie River, which flows from the lake's western end at Fort Providence northwest to the Beaufort Sea. The lake receives water from the Hay River from the south, the Slave River from the south (which carries the entire flow of the Peace and Athabasca Rivers from northern Alberta), and many other tributaries. The lake freezes from December to June. The seasonal Tibbitt to Contwoyto Winter Road across the lake's east arm and to the diamond mines of Lac de Gras supplies the diamond industry from Yellowknife each winter.

Yellowknife, the territorial capital, is on the lake's north shore. Other settlements include Fort Resolution, Fort Providence, Hay River, Behchoko, and Lutselk'e. The lake supports a commercial fishery for lake whitefish, lake trout, northern pike, walleye, inconnu, and Arctic grayling. Hay River on the south shore is the principal Canadian inland freshwater port, with annual barge traffic up the Mackenzie River to Inuvik and points north. Climate change is rapidly affecting the lake, with later freeze-up, earlier ice break-up, longer open-water season, and changes to fish and wildlife populations all documented since the 1990s. Wood Buffalo National Park (established 1922, UNESCO World Heritage Site 1983) on the southern shore protects the world's largest free-roaming bison herd.