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
Geikie River (Saskatchewan) Fond du Lac River which flows out of the lake to the north-west where it drains into Lake Athabasca which ultimately drains into the Arctic Ocean via the Mackenzie River system, or into the Cochrane River which flows out of the north-eastern side of the lake and into Reindeer Lake which drains via the Churchill River system into Hudson Bay. If Hudson Bay is defined as part of the Atlantic Ocean then the Geikie River is the largest river in the world that drains naturally into two oceans. The Geikie River is bridged by Highway 905 at the highway's 184