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
Lake Creek (Siuslaw River) Lake Creek (Siuslaw River) Lake Creek is a major tributary of the Siuslaw River in Lane County in the U.S. state of Oregon. On average, the long creek contributes about a third of the lower Siuslaw's water volume. Beginning near Prairie Mountain near the Lane–Benton county border in the Central Oregon Coast Range, Lake Creek flows generally southeast through the Siuslaw National Forest to the vicinity of Horton, then southwest through the communities of Blachly, Triangle Lake, Greenleaf, and Deadwood. It enters the Siuslaw River at Swisshome, by water from the larger stream's mouth on the Pacific Ocean at Florence.