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.
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.