Benjamin Franklin Leonard / Donald Albert Brobst / Donald K. Leifeste / Geological Survey (U.S.) / James Alfred Calkins / Kathleen T. Iseri / Maurice V. Adams / Norman J. Page / T. Leslie Youd / Wallace R. Hansen / John C. Dohrenwend / Olaf Kays / Walden P. Pratt / Walter Basil Langbein / Eleanor K. Keefer / Vincent Ellis McKelvey |