In the northern part of the province, between 53° and 54° north, all the waters of Alberta flow toward the Arctic Ocean. Starting at Mount Athabasca, the Athabasca River runs north and empties into Lake Athabasca near 58° north. North of 56° north flows through and from the Rocky Mountains as the Peace River. After descending northeastward to within a few miles of Lake Athabasca, it is met by a stream emerging from that lake. The united river carrying down the waters of the Athabasca slope is called the Slave River, which, passing through Great Slave Lake, emerges as the great Mackenzie River, which falls into the Arctic Ocean. Alberta thus gives rise to the two great rivers, the Saskatchewan and the Mackenzie.