Boats of the Mackenzie River watershed carrier business in 1947. The last steam-propelled sternwheelers, the "S.S. Distributor" and "S.S. Mackenzie" were retired around the same time. In later years, with the construction of the Mackenzie Highway from Alberta to Great Slave Lake, the importance of the Athabasca-Slave River route dwindled and NTCL operations were based from shipyards in Hay River after 1959. NTCL became the primary water operator in the Mackenzie River watershed with the purchase of Hudson's Bay Company's fleet and equipment in 1958, and the total buyout of Yellowknife Transportation Company in 1965 including its fleet of diesel tug boats. Other small commercial operators
Mackenzie River Lakes are remnants. Today's Mackenzie River is very young in geologic terms – its channel formed over a period of no more than several thousand years as the ice sheet retreated. Prior to the ice ages, only the Peel River tributary flowed through what is now the Mackenzie Delta into the Arctic Ocean. The other tributaries of the Mackenzie combined into the "Bell River" which flowed east into Hudson Bay. During glaciation the weight of the ice sheet depressed northern Canada's terrain to such an extent that when the ice retreated, the Mackenzie system was captured to lower elevations in