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
Mackenzie River watershed, reaching up to deep in the Mackenzie Delta. As a whole, the Mackenzie basin receives only meager to moderate rainfall, averaging over the entire basin, though mountain areas experience much higher precipitation, and areas near and north of the Arctic Circle receive much lower precipitation. The Mackenzie drainage basin is bordered by multiple major North American watersheds. Much of the western edge of the Mackenzie basin runs along the Continental Divide. The divide separates the Mackenzie watershed from that of the Yukon River, which flows to the Bering Strait; and the Fraser River and Columbia River systems, both of