 It then flows through a number of lakes and cities in Minnesota, including Elbow Lake, Many Point Lake, Chippewa Lake, Height of Land Lake, Frazee, the Pine lakes, Rush Lake, Otter Tail Lake and Ottertail, West Lost Lake, Fergus Falls, and Orwell Lake.At its mouth, it joins with the Bois de Sioux River to form the Red River between Breckenridge, Minnesota and Wahpeton, North Dakota.The Red River is the Minnesota–North Dakota boundary from this point onward to the Canada–United States border.