Mackenzie River from the Peace-Athabasca system are significantly slowed by the delta area at the western end of Lake Athabasca causing the lake to rise, and the excess water can only flow out after the rivers have receded. The same phenomenon occurs at Great Slave Lake, which naturally regulates the flow from the Slave River into the Mackenzie. There are river gages at several upstream points along the Mackenzie River. The average flow rate at the outlet of Great Slave Lake is . At Fort Simpson, below the Liard River, it is . At Norman Wells it is , and at the
Redknife River upstream from Jean Marie River. Redknife River The Redknife River is a river in the Northwest Territories of Canada. It is a major tributary of the Mackenzie River. The Redknife Formation, a stratigraphical unit of the Western Canadian Sedimentary Basin was named for the river. The Redknife river originates in the "Redknife Hills", at an elevation of . It flows east down the slopes of the hill, then turns north, draws water from a lake system, then turns north-east. It is crossed by the Mackenzie Highway, then turns north and flows into the Mackenzie River at an elevation of ,