Mackenzie River east into the Churchill River. The eastern portion of the Mackenzie basin is dominated by vast reaches of lake-studded boreal forest and includes many of the largest lakes in North America. By both volume and surface area, Great Bear Lake is the biggest in the watershed and third largest on the continent, with a surface area of and a volume of . Great Slave Lake is slightly smaller, with an area of and containing of water, although it is significantly deeper than Great Bear. The third major lake, Athabasca, is less than a third that size with an area of
Bistcho Lake Bistcho Lake Bistcho Lake is a large lake in north western Alberta, Canada. Bistcho Lake has a total area of (with islands area and water surface), and lies at an elevation of . It is the third largest lake in Alberta (or fourth if considering Lake Athabasca, which is partly in Saskatchewan). Bistcho Lake is located in the hydrographic basin of the Liard River, to which it is connected by the Petitot River. The waters of the lake drain to the Arctic Ocean through the Petitot, Liard and Mackenzie River. The Jackfish Point and Bistcho Lake indian reserves of the