The Athabasca River originates in Jasper National Park, in an unnamed lake at the toe of the Columbia Glacier within the Columbia Icefield, between Mount Columbia, Snow Dome, and the Winston Churchill Range, at an elevation of approximately . It travels before draining into the Peace-Athabasca Delta near Lake Athabasca south of Fort Chipewyan. From there, its waters flow north as Rivière des Rochers, then join the Peace River to form the Slave River, which empties into the Great Slave Lake and discharges through the Mackenzie River system into the Arctic Ocean. The cumulative drainage area is .