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 Ocean on 14 July 1789. The river he named "Disappointment River" would later be renamed in his honor. No European reached its mouth again until Sir John Franklin on 16 August 1825. The following year he traced the coast west until blocked by ice while John Richardson followed the coast east to the Coppermine River. In 1849 William Pullen reached the Mackenzie from the Bering Strait. In the following decades the North West Company established forts on the river, the precursors of present-day settlements such as Fort Simpson (formerly Fort of the Forks). A lucrative fur trade was carried out,