The longest river in Canada, flowing 1,700 km (1,060 miles) north-westwards from the Great Slave Lake to the Beaufort Sea, a part of the Arctic Ocean.
Definition of Mackenzie River in US English:
Mackenzie River
proper nounməˌkenzē ˈrivər
A river that flows northwest for 1,060 miles (1,700 km) from Great Slave Lake to Beaufort Sea, which is a part of the Arctic Ocean. It is the longest river in Canada.