Lake Claire (Alberta) contains Baril Lake and Mamawi Lake. The waters are discharged in the Peace River, finding their way to the Arctic Ocean through the Slave River, Great Slave Lake and Mackenzie River. Lake Claire (Alberta) Lake Claire is the largest lake which is entirely in Alberta, Canada. It is located entirely in Wood Buffalo National Park, west of Lake Athabasca. It lies between the mouths of Peace River and Athabasca River, and is part of the Peace-Athabasca Delta system. The lake has a total area of , with island area, and lies at an elevation of . It is the largest
Mackenzie River watershed drains about 20 percent of Canada. It is the largest river flowing into the Arctic from North America, and including its tributaries has a total length of , making it the thirteenth longest river system in the world. Through its many tributaries, the Mackenzie River basin covers portions of five Canadian provinces and territories – British Columbia (BC), Alberta, Saskatchewan, Yukon, and Northwest Territories. Thutade Lake, in the Northern Interior of BC, is the ultimate source of the Mackenzie River via the Finlay–Peace River system, which stretches through BC and Alberta. The Athabasca River originates further south, in Jasper