Mackenzie River great depths to bedrock. A characteristic feature of the delta is its numerous pingos, or hills of earth-covered-ice – some 1,400 of them. The Peel River, carrying much of the runoff from the northern Yukon, joins in the delta at a point northeast of Fort McPherson. Below there, the Mackenzie diverges into several large channels with the largest heading north-northeast, emptying into the Beaufort Sea west of Tuktoyaktuk. At , the Mackenzie River drainage basin encompasses nearly 20 percent of Canada. About , or 54 percent of the basin, lies above Great Slave Lake. Permafrost underlies about three-quarters of the
Rapid River (Cree River tributary) flow via the Cree River, the Fond du Lac River and the Mackenzie River to the Arctic Ocean. Rapid River (Cree River tributary) The Rapid River is a river in northern Saskatchewan, Canada. It is part of the Mackenzie River drainage basin. The Rapid River begins at an unnamed lake at an elevation of . It travels north to Kirsch Lake at an elevation of , where it takes in several unnamed tributaries, including one from the left arriving from Halliday Lake. The river continues to Parker Lake at an elevation of where it takes in the left tributary Arnold