Athabasca River is marked by rapids, impeding navigation southwest of Fort McMurray. The Athabasca River 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 joining the Peace River to form the Slave River that empties into Great Slave Lake and discharges through the Mackenzie River system into the Arctic Ocean. The cumulative drainage area is . Numerous communities are located on the banks of the Athabasca River, including Jasper, Brule, Entrance, Hinton, Whitecourt, Fort Assiniboine, Smith, Athabasca, Fort McMurray, and Fort McKay. An independent study has
Mackenzie River Bear River, the outflow of Great Bear Lake at Tulita. The Mackenzie widens considerably to about at Norman Wells, a major center of oil production. There is a narrows at the Mountain River confluence called the Sans Sault Rapids, where the Mackenzie falls about . Below the Mountain River the Mackenzie flows due north until reaching The Ramparts, a limestone gorge barely wide and up to deep. Below The Ramparts is the village of Fort Good Hope, where the Mackenzie turns northwest again, soon crossing the Arctic Circle. The Mackenzie here flows slightly lower in elevation than the surrounding tundra,