4241 km is therefore 2545miles long. Only Lakes Superior, Huron, and Michigan are larger. The lake spreads across parts of two of Canada's major land regions, the Canadian Shield and the northern Interior Plains. Part of the lake also lies within the Arctic Circle.
Ice covers the lake for about three-fourths of the year.
The lake's Dease Arm and McTavish Arm extend north into the tundra, which is a dry, cold, treeless region. Forests of small trees line the shores of the rest of Great Bear Lake. The Great Bear River drains the lake into the Mackenzie River and becomes part of Canada's longest navigable river system. Great Bear Lake contains many fish, including trout, whitefish, and northern pike. The region around the lake has abundant wildlife.