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
Cass River (Mackenzie District) Cass River (Mackenzie District) The Cass River is an alpine river in the Canterbury Region of the South Island of New Zealand. It rises in the Hall Range immediately below Rankin Pass, and also receives water from the nearby Huxley Glacier. After dropping very rabidly the river flows south with braided channels along a flat-bottomed valley for . The Leibig Range and Gamack Range are to the west, and the Haszard Range to the east. The river flows into the west side of Lake Tekapo where it has built up a gravel delta. The Cass River is named for Thomas