Great Slave Lake, 28 568 km2, elevation 156 m, fifth-largest lake in North America, tenth in the world, is located in south-central NWT. It was named by Samuel Hearne after the Slavey.

Great Slave, along with Great Bear, Athabasca and a tangled chain of lakes between, are remnants of a single postglacial pool. Its southern and eastern shores cut into the granite edge of the Canadian Shield; to the north and west lie the Barren Lands. Cold, very deep (614 m) and frozen 8 months of the year, Great Slave is a vast reservoir for numerous rivers and streams which spill over the crest of the Shield. Among these are the Yellowknife, Snare, Emile, Beaulieu, Snowdrift, Taltson and Hay; the Slave River carries the waters of the Peace River past thick forest into the flat, grassy marshes of the delta on the southern shore of the lake. The great Mackenzie River issues from the extreme west end.


Alexander Mackenzie found the outlet in 1789, but the lake was first crossed by Hearne in the winter of 1771. The Chipewyan of the area carried furs to Hudson Bay as early as the 1730s, and the fur trade dominated the economy almost to WWII. The earliest settlements in the area were Hudson's Bay Co posts: Fort Resolution, Fort Rae (now Behchokò), Fort Providence and Fort Reliance.

Robert Bell conducted the first survey (1899) and described the area's mineral potential. Klondike-bound travellers prospected in the area, but the gold rush came in 1934, when gold was discovered in the volcanic rock west of Yellowknife Bay. Next year the Town of Yellowknife was established. The mining of the huge lead-zinc deposits southwest of the lake from 1964-1988 began after the completion of the Great Slave Lake Railway to Hay River and Pine Point and the construction of a hydroelectric plant on Taltson River. A prosperous commercial fishery centered on the Hay River dates from 1945; the chief catch is whitefish.

The all-weather Mackenzie Highway, begun in 1945, is paved to Hay River; its terminus is Yellowknife. Great Slave has long been part of the Peace-Mackenzie waterway, and tugs and barges still ply the lake, though it is susceptible to savage storms.

Portions of the East Arm have been put aside for the future establishment of a national park.