Great Bear Lake

Great Bear Lake is a large, cold, deep lake, in the Northwest Territories, Canada. It is one of the largest lakes on Planet Earth, and the largest lake found entirely in Canada. Like Lake Baikal its depth is due to it being a rift lake.

The area around Great Bear Lake is very sparsely settled, with only a single permanent settlement at Deline, where the Bear River drains the lake to the Mackenzie River.

Ice prevents navigation of the lake for over half the year.

Early in the 20th century prospectors found deposits of Radium and Uranium on the eastern shore of the lake, at Port Radium. The mine at Port Radium supplied most of the Uranium for the Manhattan Project. Ore was loaded into sacks, which were piled on to barges, and towed across the lake, down the Bear River, and the Mackenzie River system to Waterways, Alberta, which was then the northern terminus of the North American railway grid.

Inadequate safety precautions were taken, and many of the First Nations people who worked as deck hands on the tugs and barges became sick from exposure to radiation.