Great Bear Lake, largest lake of Canada and fourth largest of North America, c.12,275 sq mi (31,800 sq km), c.190 mi (310 km) long and from 25 to 110 mi (40–177 km) wide, Northwest Territories, on the edge of the Canadian Shield. It is drained to the W by the Great Bear River (c.100 mi/160 km long), which flows into the Mackenzie River. Even though it is one of North America's deepest (1,356 ft/413 m) lakes, its waters are open only about four months each year. The lake was explored (c.1800) by traders of the North West Company, and a trading post was later established there. Déline (formerly Fort Franklin), on the southwest shore, was built by Sir John Franklin Franklin, Sir John, 1786–1847, British explorer in N Canada whose disappearance caused a widespread search of the Arctic. Entering the navy in 1801, he fought in the battle of Trafalgar.
..... Click the link for more information. , a British explorer, in 1825. Discoveries of rich radium ores, which are now exhausted, on the eastern side of the lake in 1930 caused much mining activity in the years immediately following; the Eldorado Mines, at Port Radium, were located there.

Great Bear Lake

Lake, Northwest Territories, Canada. Lying astride the Arctic Circle, it was visited before 1800 by North West Company traders and later named for the bears that inhabited its shores. Containing many small islands, Great Bear Lake is roughly 200 mi (320 km) long and 25–110 mi (40–175 km) wide and has a maximum depth of 1,356 ft (413 m). It is the largest lake entirely within Canada and the fourth largest in North America. The lake's waters abound with fish, including the speckled trout.

Great Bear Lake

a lake in NW Canada, in the Northwest Territories: the largest freshwater lake entirely in Canada; drained by the Great Bear River, which flows to the Mackenzie River. Area: 31 792 sq. km (12 275 sq. miles)