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.
Missouri River
To the north, the much lower Laurentian Divide separates the Missouri River watershed from those of the Oldman River, a tributary of the South Saskatchewan River, as well as the Souris, Sheyenne, and smaller tributaries of the Red River of the North. All of these streams are part of Canada's Nelson River drainage basin, which empties into Hudson Bay. There are also several large endorheic basins between the Missouri and Nelson watersheds in southern Alberta and Saskatchewan. The Minnesota and Des Moines Rivers, tributaries of the upper Mississippi, drain most of the area bordering the eastern side of the Missouri River basin. Finally, on the south, the Ozark Mountains and other low divides through central Missouri, Kansas and Colorado separate the Missouri watershed from those of the White River and Arkansas River, also tributaries of the Mississippi River.