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.
Sacramento River
The major drainage basins bordering that of the Sacramento are that of the Klamath in the north, the San Joaquin and Mokelumne to the south and the Eel River in the west. The Russian River also lies to the west and the endorheic (closed) Honey Lake and Eagle Lake basins to the north. On the east side are many endorheic watersheds of the Great Basin including the Truckee River and Carson River. Parts of the Sacramento watershed come very close to, but do not extend past, the border of California and Nevada.