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
Cass River (Mackenzie District) Cass River (Mackenzie District) The Cass River is an alpine river in the Canterbury Region of the South Island of New Zealand. It rises in the Hall Range immediately below Rankin Pass, and also receives water from the nearby Huxley Glacier. After dropping very rabidly the river flows south with braided channels along a flat-bottomed valley for . The Leibig Range and Gamack Range are to the west, and the Haszard Range to the east. The river flows into the west side of Lake Tekapo where it has built up a gravel delta. The Cass River is named for Thomas