Correspondence
The correspondence series dates from 1871 to 1935 and relates to his career as state geologist, a member of the University of Michigan Board of Regents, his business career, and his literary interests. His correspondents include Rolland C. Allen, Henry M. Bates, Junius E. Beal, William W. Bishop, Aaron T. Bliss, Julius C. Burrows, Marion L. Burton, William L. Clements, Mortimer E. Cooley, Charles A. Davis, Woodbridge N. Ferris, Fred W. Green, William H. Hobbs, Jacob Houghton, Harry B. Hutchins, Francis W. Kelsey, Frank Knox, Theodore W. Koch, Edward H. Kraus, Alfred C. Lane, Clarence C. Little, James O. Murfin, Chase S. Osborn, Gifford Pinchot, John T. Rich, Filibert Roth, Israel C. Russell, Alexander G. Ruthven, Walter H. Sawyer, Albert E. Sleeper, Shirley W. Smith, William A. Smith, Ralph Stone, Marshman E. Wadsworth, Fred M. Warner, Peter Q. White, and H. Olin Young.