Answer:
(1,080 mi) long
Step-by-step explanation:
The Mackenzie River is a river in the Canadian boreal forest. It is the longest river system in ... Basin size, 1,805,200 km2 (697,000 sq mi) ... The river's main stem is 1,738 kilometres (1,080 mi) long, flowing north-northwest from Great ... of the Mackenzie River is Thutade Lake, in the Northern Interior of British Columbia.