1. Peat deposits of Koochiching County Minnesota showing locations of drainage ditches.
1919. Scale [1:253,240] (W 94°25ʹ00ʺ--W 93°04ʹ00ʺ/N 48°42ʹ00ʺ--N 47°50ʹ00ʺ). "Compiled from maps of U.S. land office county map. Drainage map and field n...