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
Turnagain River Turnagain River The Turnagain River is a river in the Canadian province of British Columbia. The Turnagain River was named by Samuel Black of the Hudson's Bay Company, who in 1824 journeyed to the river before turning back. Part of the river flows through the Muskwa-Kechika Management Area. The Turnagain River flows generally east and north to join the Kechika River. The Kechika River is a tributary of the Liard River, which is in turn tributary to the Mackenzie River, which empties into the Arctic Ocean. A notable tributary is the Cassiar River, which flows north to joins the Turnagain