The Otter Tail River watershed includes three general physiographic areas- a moraine and ice-contact area, an outwash plain, and the plain of Glacial Lake Agassiz.
The moraine and ice-contact area is a fairly rugged complex of hills characterized by local relief of several hundred feet in some areas, particularly in the extreme north and southeastern parts of the watershed. The outwash plain is fairly flat to rolling and the Glacial Lake Agassiz plain is extremely flat.
The watershed has an area of about 1,920 square miles and includes parts of Becker, Otter Tail, Wilkin, and Clearwater Counties. The population of the area is about 55,500; 32,600 urban and 22,900 rural. The economy is largely agricultural. Grain farming is dominant, but dairying is important.
The extremely large number of lakes in the area provides a basis for a large recreation-based economy.
Water resources of the Otter Tail River Watershed, West-central Minnesota