River, southwestern and southern central Canada.
The largest river system of Alberta and Saskatchewan, it rises in the Canadian Rockies as the North and South Saskatchewan rivers, which are 800 mi (1,287 km) and 865 mi (1,392 km) long, respectively. The combined streams continue east 340 mi (550 km) to enter Lake Winnipeg . Once important as a fur-trading route, it now provides hydroelectric power and irrigation.