Emerson G. Crosthwaite, James Kincheon Searcy, John Augustus Baker, Loyd L. Young, Miles LeRoy Eddards, W. C. Griffin, W. H. Robinson, L. R. Kister, William Evans Price, William James Powell, Glenn Scarcia, Herbert Alfred Swenson · 1949
Benton M. Wilmoth, Geological Survey (U.S.). Water Resources Division, Howard Frederick Matthai, Miles LeRoy Eddards, R. W. Carter, Roger Warren Swanson, W. C. Griffin, W. H. Robinson, L. R. Kister, Lois Emily Randall, William James Powell, Arthur Johnson, Glenn Scarcia, Herbert Alfred Swenson · 1956