Collection includes correspondence, articles, papers and stories, manuscripts and galleys of books, a bibliography of his writings, and research and lecture notes pertaining to vertebrate ecology, population dynamics and professional organizations including American Ornithologists' Union, Iowa Conservation Commission, Ecology Society, National Audubon Society and the Wildlife Society. Manuscripts and galleys for his books include: Muskrats and marsh management (1961), Muskrat populations (1963), Of men and marshes (1957), Of predation and life (1967), and The red gods call (1973). Correspondents include Durward L. Allen, Marston Bates, Kai Curry-Lindahl, Jay N. Darling, Charles Elton, Ira N. Gabrielson, Joe Hickey, David Lack, A. Starker Leopold, Aldo Leopold, G.W. Malaher, W.L. McAtee, Margaret M. Nice, Lauri Siivonen, Herbert L. Stoddard, and William Vogt.
