The main body of the Mackenzie River is 1,738 kilometers long, making it the longest river in Canada and the second longest in North America, after the Mississippi. The Mackenzie River system, which includes tributaries such as the Leard River, has a total area or spread of 4,241 km. The Mackenzie River flows northwest through the Northwest Territories from Great Slave Lake to the Beaufort Sea (north of the Yokon in Canada and Alaska in the US). Its total drainage basin — 1.8 million km-square — has the largest flow of any Canadian river at 9,700 cubic-m. / second, second only to St. Lawrence. The highest flow of the river occurs in June, when the ice melt is almost over and due to the presence of two large and flat lakes east of the river. Ice breakup begins on the Liard River in late April, early May. The river is ice-free from early June and lasts until about November.
The Mackenzie River plays a dominant role in the regional sea in the southeastern Beaufort Sea. Annually, about 325 cubic-km. Freshwater and 85 million tons of sediment flow through the Mackenzie Delta to the Canadian Beaufort Shelf. Sediment-loading by northwesterly winds and the effect of earth’s rotation diverts the flow of the Mackenzie River to the east, while easterly winds flow in the opposite direction.
Mackenzie River Delta (Delta):
The Mackenzie Delta is a low-lying alluvial delta, covered with a canopy of black spruce trees, becoming lighter as one goes north. These trees are large enough to be used in log building construction and are widely used as fuel. The delta is 80 km. Across, bounded by the Richardson Mountains to the west and the Cariboo Mountains to the east. The delta divides the river into three main waterways: the Eastern Channel, which flows past Inuvik at the eastern end of the delta; to the west the Peel Channel, which flows past Aklavik; and the Middle Channel, which carries the main outflow to the Beaufort Sea.
Ecology and Environment:
As snow melts and large ice floes break up in the spring and summer, the waters of the Mackenzie River become heavy with dissolved sediment and solids. The river carries a large load of such material throughout the year. Much of this solid material originates in other mountain ranges, including the Mackenzie Mountains, which drain westward into the Mackenzie River and into the Leard sub-basin. In contrast, the water flowing from the Great Bear River to the east is cleaner.
There are 54 species of fish found in the rivers, many of which congregate in the waters of the Mackenzie and its tributaries. Some fish move from the ocean to freshwater and migrate up the Mackenzie and Liard Rivers.
Migratory birds, including tundra swans and sandhill cranes, use the Mackenzie River as a migration route and spend the summer months in the delta. In the spring, the delta is home to birthing and rearing beluga whales. The maze of channels that make up the delta is also home to a thriving muskrat population that has long sustained the fur industry. In addition, moose, mink, beaver and a type of frog are all found along the river.
As with other northern aquatic ecosystems, climate change and pollution, particularly heavy-duty pollution, pose the greatest concern for the health of plants, animals, people and fish living in and around the Mackenzie River. Hazards from climate change are already seen along the Mackenzie, including unusual flooding and reduced ice density. There are concerns that oil and gas exploration drilling will expose waste and further pollute the local environment. Future changes in streamflow are also expected as a result of warming. Since the mid-1980s, barbote fish (members of the cod family that live in freshwater), a top prey in the Mackenzie River and an important food source for local communities, have had significant increases in toxicant levels. Mercury is flowing from the Mackenzie River into the Beaufort Sea and the Arctic Ocean, where it is causing concern for beluga whales and other species.
History:
Deh Cho, the Deya Dene name of the Mackenzie River aborigines, literally translated into Bengali as “big river”; Or Kawukpak which means “great river”. The English name derives from British navigator Alexander Mackenzie, who was the first European to travel the length of the Mackenzie River from its source to its outlet in the ocean in 1789.
The Inuvialuit lived in a village called Kukpak from the 14th to the end of the 19th century. It was located near the ocean at the mouth of the Mackenzie River. The settlement was later abandoned due to European-introduced disease epidemics. At Kukpa, the Inuvialuit lived by hunting caribou and beluga whales. Hundreds of years ago there were fish camps along the main stem of the Mackenzie River. Families used to collect fish from the river. As summer turned, caribou would migrate inland to hunt in the Mackenzie Mountains or eastward on the tundra. Explorers Alexander Mackenzie and John Franklin both visited fish camps along the river during their travels in 1789 and 1825 respectively. River fisheries increased in importance for sled dog teams during the early fur trade era, as dry fish was the dogs’ main subsistence during the winter months.
The Mackenzie River’s relative ease of navigation made it a focus of activity for non-Aboriginal newcomers, including explorers, traders and missionaries. The North West Company established a post along the river, later used by the Hudson’s Bay Company as a district headquarters, named ‘Fort Good Hope’.
In the summer of 1920, Canadian Imperial Oil workers searched for oil along the river. The Canadian government then signed Treaty 11 with Aboriginal peoples to secure title to these lands. The discovery of oil led to the development of a refinery in Norman Wells, along with mining and supplying petroleum products to regional industrial activities in the capital Yellowknife in the early 1930s.
Twentieth-century transportation in the Northwest Territories was 100 percent dependent on the Mackenzie River. The Hudson’s Bay Company’s flagship supply ship, the S.S. The Distributor was one of several stern-wheeler motorized vessels that plied the length of the main body of the river, up to Aklavik in the delta. Aboriginal Metis men often captained these vessels. Distributor ships made two or three round trips each summer from the 1920s to the late 1940s. Distributors carry goods and personnel to posts, hospitals and missions, as well as students attending residential schools in the north.
In 1942, construction began on the Canole Pipeline to carry crude oil to Whitehorse, Yukon. CANOL was one of several US Army projects in the Northwest Territories during World War II specifically devoted to ensuring continental security and energy security. Hundreds of American soldiers traveled the Mackenzie River, which served as an important transportation artery not only for the canals, but also for other military projects. The indigenous Danes also found work on these projects, as they aided in movement and guided survey workers.
After 1940, greater efforts were made to build all-weather highways in the Northwest Territories. Work progressed slowly and ended in the 1960s, although the waterways persisted into the 21st century. There are also winter ice-roads in the delta as part of the NWT Highway. In 2012, the ‘Deh Cho’ bridge over the river was inaugurated, the only permanent bridge over the river.
Despite sparse evidence, prehistoric humans are thought to have arrived in the Mackenzie Valley during the early human migration from Asia to North America 10,000 years ago. There have been settlements along the river for thousands of years. The river was the main waterway for early European explorers traveling into Canada’s northern interior. The great Mackenzie River played a vital role in Canada’s economy as it prospered in transportation and trade.
Scarborough, Canada
