Mackenzie River Great Slave Lake, at Fort Resolution, Northwest Territories. The Slave is by far the largest river flowing into the lake, with an annual flow of 108 km (87 million acre-feet). It contributes about 77% of the overall inflow, and forms a large delta where it enters the lake. Other rivers entering Great Slave Lake area the Taltson, Lockhart and Hay Rivers, the latter of which also extends into Alberta and BC. The Mackenzie River issues from the western end of Great Slave Lake about south-west of Yellowknife. The channel is initially several kilometres wide but narrows to about at Fort
Mackenzie River Arctic Red confluence it is . Mackenzie monthly mean discharge at Arctic Red River (m/s)<br> As recently as the last glacial maximum about 30,000 years ago, the majority of northern Canada was buried under the enormous continental Laurentide ice sheet. The tremendous erosive powers of the Laurentide and its predecessors, at maximum extent, completely buried what is now the Mackenzie watershed under thousands of metres of ice and flattened the eastern portions of the watershed. When the ice sheet receded for the last time, it left a long postglacial lake, Lake McConnell, of which Great Bear, Great Slave and Athabasca