List of longest rivers of Canada
Nine rivers in this list cross international boundaries or form them. Four—the Yukon, Columbia, Porcupine, and Kootenay—begin in Canada and flow into the United States. Five—the Milk, Pend d'Oreille, Saint Lawrence, Red, and Saint John—begin in the United States and flow into Canada. Of these, the Milk and the Kootenay cross the international border twice, the Milk leaving and then re-entering the United States, the Kootenay leaving and then re-entering Canada. The drainage basins of these nine rivers extend into both countries; in addition, the drainage basins of six others—the Fraser, Assiniboine, South Saskatchewan, Saskatchewan, Nelson, and Winnipeg—extend into the United States even though their main stems flow entirely within Canada.
Drainage basin
The five largest river basins (by area), from largest to smallest, are the basins of the Amazon (7M km), the Congo (4M km), the Nile (3.4M km), the Río de la Plata (3.2M km), and the Mississippi (3M km). The three rivers that drain the most water, from most to least, are the Amazon, Ganga, and Congo rivers.