Base source: USGS 1:100,000 county base map dated 1975; interpretations derived from soil map constructed 1973.; "Projection and 10,000-metre grid ticks, zone 14, Universal Transverse Mercator. 25,000-foot grid ticks based on South Dakota coordinate system, south zone."; Feb. 1978.; Includes location map. 112 x 92 centimeters Scale 1:50,000