Soil Map of the United States, Section 2. Atlas of American Agriculture.
Soil Map of the United States by Curtis F. Marbut and Associates in the Soil Survery, U.S. Department of Agriculture, F.J. Marschner, Cartographer and Associate in Compilation. 1931. Soils, Plate 5, Section 2. Lith. A. Hoen & Co., Inc. Atlas of American Agriculture.
David RumseyMarbut, Curtis F.
1931
1936
U.S. Department of Agriculture
1:2 500 000