Upper Summit Lake (British Columbia) River, Great Slave Lake and the Mackenzie River into the Beaufort Sea portion of the Arctic Ocean. Upper Summit Lake (British Columbia) Upper Summit Lake is a lake in Regional District of Fraser-Fort George, in the Central Interior of British Columbia, Canada, about north of the city of Prince George and south of the community of Bear Lake. It lies just west of Highway 97 (John Hart Highway). Upper Summit Lake is about long and wide, and lies at an elevation of . There are no inflows, and an unnamed creek flows from the southern tip of the lake to
Lake Athabasca depth of , and holds of water, making it the largest and deepest lake in both Alberta and Saskatchewan, and the eighth largest in Canada. Water flows northward from the lake via the Slave River and Mackenzie River systems, eventually reaching the Arctic Ocean. Fort Chipewyan, one of the oldest European settlements in Alberta, is located on the western shore of the lake, where the Rivière des Rochers drains the lake and flows toward Slave River, beginning its northward journey along the eastern boundary of Wood Buffalo National Park. The eastern section of the lake narrows to a width of