What is the longest river in Canada?

The Mackenzie River is the longest Canadian river and the largest river system in the country. It flows from North America to the Arctic Ocean, running 1,080 miles (1,738 kilometers) in a northerly direction. Through the Mackenzie Delta, the Mackenzie River empties into the Beaufort Sea, which is a marginal sea west of Canada’s Arctic Islands and north of Alaska, Yukon, and the Northwest Territories.

The drainage basin or watershed of the Mackenzie River encompasses close to 20 percent of Canada, making it the largest in the country. The river, along with its tributaries, covers portions of 5 territories and provinces – the Northwest Territories, Saskatchewan, Yukon, Alberta, and British Columbia.

The largest tributaries of the Mackenzie River are Liard River, North Nahanni River, Root River, Redstone River, and others. The Liard River drains about 277,000 sq. km. of muskeg and boreal forest and flows through British Columbia, Yukon, and the Northwest Territories. North Nahanni River is another major tributary in the Northwest Territories, which originates in the Mackenzie Mountains. The river receives waters from several tributaries, among which Ram River, Battlement Creek, and Deceiver Creek. The Mackenzie River includes 3 major lakes as well, Athabasca, Great Bear, and Great Slave and covers a distance of about 1,800 km. The river spans 4 physiographic regions – Arctic Coastal Plain, Precambrian Shield, Interior Plain, and Western Cordillera.

The river’s drainage basin is among the most intact and largest ecosystems on the North American continent. About 63 percent of the basin or 439,000 sq. miles (1,137,000 sq. km) is covered by forests. Wetlands and boreal cover 18 percent of the basin, and virgin forests comprise most of the wooded areas.

There are 54 fish species, but none of them is indigenous. Fish species include lake whitefish, minnows, the northern pike, and others. The shores of the river are lined with willows, dwarf birch, and other plant species, and vegetation transitions to popular forest, aspen, and black spruce to the south. Due to the cold climate, the northern basin is not ecologically diverse.

Migratory birds use the Peace-Athabasca Delta and the Mackenzie Delta, which are important breeding and resting areas. Endangered species have been catalogued in the area, including the peregrine falcon, whooping crane, and bald eagle. Ecologists have catalogued 215 species in total. The Mackenzie Delta also comprises a large number of low-lying alluvial islands. The islands are mostly covered with black spruce, with trees being used as fuel and for the construction of log buildings. The Mackenzie Delta is 80 kilometers across, and it is a maze of circular ponds, cutoff lakes, and channels. It is bordered by the Caribou Hills to the east and the Richardson Mountains to the west.

The Mackenzie River is a key transportation link during the ice-free season, linking many isolated and scattered communities. The northernmost railhead of Canada is found on the Great Slave Lake’s south shore, in the town of Hay River. Goods are shipped there by truck and train and then are transported by the Northern Transportation Company, which is Inuit-owned.