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.
Eastern forest-boreal transition
The ecoregion includes most of the southern Canadian Shield in Ontario and Quebec north and west of the Saint Lawrence River lowlands including the eastern shores of Lake Superior and other areas of the Great Lakes, Lake Timiskaming, the southern Laurentian Mountains, Lake Nipissing, Quebec City, the Saguenay River and parts of Georgian Bay, Greater Sudbury/North Bay, Ontario, Saguenay, Quebec, the Clay Belt and Temagami in Ontario. There is a separate section of the ecoregion in the Adirondack Mountains in upper New York State, United States. However the higher elevations of the Laurentian Mountains and the northern Appalachian Mountains in Canada constitute the Eastern Canadian forests ecoregion.