Saskatchewan, a river of British North America, in the Northwest territories, the upper course consisting of two branches. The North branch, issuing from Glacier lake on the E. slope of the Rocky mountains, in lat. 51° 54' N., lon. 117° 30' W., flows E. past the base of Mt. Murchison, and then generally E. N. E. to its junction with the South branch near lon. 105°, 12 m. above Fort a la Corne. The latter branch, formed by the junction of the Bow and Belly rivers from the Rocky mountains in lat. 49° 40', lon. 111° 40', flows N. E. to Chesterfield, where it receives the Red Deer river, then E. N. E. to the junction with the North branch. The main river thus formed, called by the Crees Kisiskachewan (swift current), flows N. E. to the bend on the parallel of 54°, then S. E. to Cedar lake, from which it flows E. to the N. W. extremity of Lake Winnipeg. The area of the entire basin is 240,000 sq. m. From the source of the North branch to the junction the distance is about 550 m., and the length of the main river is about 200 m.

The basins of both branches are generally too wild and mountainous, and the climate is too rigorous, to admit of much cultivation; but S. of the North branch is a fertile belt, to portions of which the Hudson Bay company reserves its rights since its surrender of territorial and governmental privileges in 1869. The mountains are heavily timbered. On both branches coal and iron are found. Bisons, rapidly disappearing in the Northwest territories, are now chiefly found on the North branch. The valley of the main river, except along its lower course, presents the best agricultural region with good grazing land. The river is frozen from the middle of November to the middle of April, and in summer is navigable by the Hudson Bay company's boats, though the North branch has a rapid current and shallow channel obstructed by bowlders. The settlements and stations are distant from the river and near the lakes on account of the fish, which are there abundant. Nelson river, which issues from the N. extremity of Lake Winnipeg, is treated by some authorities as a continuation of the Saskatchewan, adding 350 m. to its length. (See Nelson River).