Mackenzie River
At , the Mackenzie River drainage basin encompasses nearly 20 percent of Canada. About , or 54 percent of the basin, lies above Great Slave Lake. Permafrost underlies about three-quarters of the 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.
Geography of Canada
The continental divide in the Rockies separates the Pacific watershed in British Columbia and Yukon from the Arctic and Hudson Bay watersheds. This watershed irrigates the agriculturally important areas of inner British Columbia (such as the Okanagan and Kootenay valleys), and is used to produce hydroelectricity. Major elements are the Yukon, Columbia and Fraser rivers.