Mackenzie River

Mackenzie River, in northwestern Canada, flowing from Great Slave Lake to the Arctic Ocean. The Mackenzie, which drains the northern portion of the Great Plains, is about 1,120 mi (1,800 km) long and is the main channel of the Finlay-Peace-Mackenzie river system (2,600 mi/4,180 km). It is navigable from June to Oct. only.

See also: Mackenzie, Sir Alexander.