Canada's Longest River: The Mackenzie River System

The Mackenzie River is Canada's longest river and the second-longest in North America (after the Mississippi).

Key Facts

• Length: 4,241 km (2,635 mi) — main stem.
• Basin Area: 1,805,200 km² (697,000 sq mi) — 2nd largest in Canada (after Hudson Bay).
• Source: Confluence of Slave River (from Peace + Athabasca) and Liard River near Fort Simpson, NT.
• Mouth: Beaufort Sea (Arctic Ocean), via vast delta.
• Provinces/Territories: BC, AB, SK, NT, YT (basin).

Major Tributaries

• Peace River (1,923 km)
• Athabasca River (1,231 km)
• Liard River (1,115 km)
• South Nahanni River (540 km) — UNESCO site, Virginia Falls.
• Peel River (580 km)
• Great Bear River (113 km) — from Great Bear Lake.

Significance

• Transport: Summer barge route to Arctic communities (Tulita, Norman Wells, Inuvik, Tuktoyaktuk).
• Hydropower: Potential (controversial); some tributary dams.
• Ecology: Critical for migratory birds, beluga whales, fish (inconnu, whitefish).
• Indigenous: Dene, Gwich'in, Inuvialuit homeland for millennia.

The Mackenzie is the circulatory system of Canada's northwestern boreal and Arctic regions.