Indian mounds of Wisconsin / Robert A. Birmingham and Amy L. Rosebrough.
More mounds were built by ancient Native Americans in Wisconsin than in any other region of North America--between 15,000 and 20,000, at least 4,000 of which remain today. Most impressive are the effigy mounds, huge earthworks sculpted in the shapes of thunderbirds, water panthers, and other forms,...
Madison, Wisconsin :
University of Wisconsin Press,