Mackenzie River Mackenzie River The Mackenzie River (Slavey language: Deh-Cho , "big river" or Inuvialuktun: Kuukpak , "great river"; ) is the longest river system in Canada, and has the second largest drainage basin of any North American river after the Mississippi River. The Mackenzie River flows through a vast, thinly populated region of forest and tundra entirely within the Canadian Northwest Territories, although its many tributaries reach into four other Canadian provinces and territories. The river's main stem is long, flowing north-northwest from Great Slave Lake into the Arctic Ocean, where it forms a large delta at its mouth. Its extensive
Boats of the Mackenzie River watershed Landing north of Edmonton to the Slave River rapids, the only significant obstacle en route to the Mackenzie. In 1886, the S.S. "Wrigley" was launched on the other side of these rapids, at Fort Smith, and for the first time a steam-driven vessel operated on the Mackenzie River as far as Aklavik in the river delta before it spilled into the Arctic Ocean. A series of small portage trails were established between Smith's Landing (later Fort Fitzgerald) and Fort Smith to skirt the 16-mile rapids - this was later upgraded into a full road in the 1920s. In 1898 the