The Sauk River watershed covers 667,200 acres (1,043 square miles) and extends from the Mississippi River near St. Cloud to within 3 miles of Alexandria. The overall watershed is about 75 miles in length. The Sauk River itself meanders for 120 miles in a northwest-to-southeast direction.
Many water bodies — both lake and rivers — in the Sauk River watershed are impaired for excess nutrients and sediment.