U.S. Department of Agriculture, Bureau of Soils ; state of Wisconsin Geological and Natural History Survey ; College of Agriculture, University of Wisconsin
"Soils surveyed by L.R. Schoenman and F.L. Musback of the Wisconsin Geological and Natural History Survey and W.J. Geib, Guy Conrey, and Arthur E. Taylor of the U.S. Department of Agriculture."
"Base map in part from U.S. Geological Survey sheet."