Hudson Bay drainage basin
The Hudson Bay drainage basin is the drainage basin in northern North America where surface water empties into Hudson Bay and adjoining waters. Spanning an area of about , the basin is almost totally in Canada (spanning parts of the Prairies, central and northern Canada), with a small portion in the United States (in Montana, the Dakotas, and Minnesota). The watershed's headwaters are in part on the Continental Divide of the Americas, and the watershed's connection to the Labrador Sea is at the Hudson Strait's mouth between Resolution Island in the Qikiqtaaluk Region and Cape Chidley on the Labrador Peninsula. On the Continental Divide the basin is bounded at Triple Divide Peak to the south, and Snow Dome to the north.
Western Canada
The Canadian Rockies are part of a major continental divide that extends north and south through western North America and western South America. The continental divide also defines much of the border between Alberta and British Columbia. The Columbia and the Fraser Rivers have their headwaters in the Canadian Rockies and are the second- and third-largest rivers, respectively, to drain to the west coast of North America. To the west of their headwaters, across the Rocky Mountain Trench, is a second belt of mountains, the Columbia Mountains, comprising the Selkirk, Purcell, Monashee and Cariboo Mountains sub-ranges.