Saskatchewan, one of the great and navigable rivers of Canada, rises among the Rockies in two great branches, called respectively the North and South Saskatchewan, 770 and 810 m., which flowing generally E., unite, and after a course of 282 m. pass into Lake Winnipeg, whence it issues as the Nelson, and flows 400 m. NE. to Hudson's Bay. The upper branches traverse and give their name to one of the western territories of Canada.