The Mackenzie River is the longest river in Canada covering a distance of around 1800 km. It begins at Great Slave Lake in the Northwest Territories and flows north into the Arctic Ocean, discharging 306 cubic kilometres of water per year (including 100 million tons of sediment). It is the main stem of the second largest river system in North America (after the Mississippi-Missouri river system), and the fourth largest of all river systems discharging into the Arctic Ocean (the three largest are in Russia). The entire Mackenzie river system extends 4250 km and drains 1.8 million sq. km. It includes three major lakes (Great Slave, Great Bear and Athabasca) and numerous major rivers (such as the Peace, Athabasca, Liard, Hay, Peel, South Nahanni and Slave rivers). It spans four physiographic regions: Western Cordillera, Interior Plain, Precambrian Shield and Arctic Coastal Plain.

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