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 Providence, which was historically an important ferry crossing in the summer, and used as an ice bridge in the winter for traffic along the Yellowknife Highway. In 2012 the Deh Cho Bridge was completed at a point about upstream, providing a safer permanent crossing. It is the only bridge across the main stem of the Mackenzie. West of Fort Providence the Mackenzie widens considerably, resembling a shallow, swampy lake more than a river; one large widening here is known as Mills Lake. After heading west for about the Mackenzie narrows and turns northwest through a long stretch of fast water