- Arnold L. Nelson, Arvid John Johnson, Bradford Knapp, Charles Ellsworth Gage, Curtis Benton, Cyril Oliver Bratley, D. F. Fisher, E. H. Siegler, Edmund Lambert, Floyd Franklin Smith, Forrest Vern Owen, Frederick James Stevenson, George Arceneaux, George McMillan Darrow, Hazel Katherine Stiebeling, James Herbert Beattie, Loyd William Brannon, Robert Roland Farrar, Van E. Romney, Waldo Lee McAtee, Wayne Melville Bever, William Henry Burrows, William Ogilvie Fraser, William Taylor Miller, United States. Department of Agriculture, Arthur Steele Mason, Charles Frederick Clark, Don Juan Slater, Esther Funnell Phipard, Francis Munger, Harry Humfeld, Howard W. Johnson, I. E. Stokes, Jacob Martin Lutz, Joseph Patrick Quinn, Thomas Laffin Baggette, Victor Rickman Boswell, Wesley Pillsbury Flint, Woodrow Wilson Bailey, John McDowell McCown, Lloyd E. Smith, Talbott Elson Clarke
· 1939
- Albert Rudolf Leding, Alexander Campbell Martin, Arnon Lewis Mehring, Arthur Henry Senner, Arthur T. Sweet, Auton William Skuderna, Benjamin Ralph Stauber, C. C. Plummer, C. H. Hadley, Chalmers Jackson King, Curtis May, Curtis Paul Clausen, David A. Savage, David Griffiths, Ernest Victor Abbott, Floyd Franklin Smith, Frederick Charles Lincoln, George Arceneaux, Glenn Gardner Hahn, Harold F. Scholz, Harold Glenn Meginnis, Harold Hall McKinney, Harry Baker Humphrey, J. Clark Salyer, James Fitton Couch, James Herbert Beattie, Jenkin William Jones, John Morrison Cooper, John Robert Parker, Kurt Walter Franke, Lewis Alexander Hurst, Mayne Reid Coe, Orator Fuller Cook, Paul George Russell, Paul Mehl, Paul William Miller, R. A. Blanchard, R. T. Balch, Ralph P. Hotis, Robert J. Sim, Robert Max Merrill, Theodore Bergen Manny, United States. Division of Silvics, Walter Ernest Fleming, Wilbur Clifford Edmundson, Wilbur Magruder Hurst, Wilfred Wickes Ballard, William Middleton, United States. Department of Agriculture, Asa Young Willis, Avis Jenkin Peterson, Claude Hope, Frederick William Metzger, I. E. Stokes, Ira Myron Hawley, J. I. Lauritzen, James Robert McCalmont, John Adam Stoehr, John Walter Taylor, Ralph Brownson Bisland, Victor Rickman Boswell, Walter Raymond Humphries, Wayne Crocker Nason, William Ernest Stone, Charles Conrad Krumbhaar, E. E. Hall, Max Raymond Osburn, Roland McKee
· 1933
- Ralph U. Cotter, C. A. Magoon, Charles Brooks, Charles Faye Sarle, Charles Otis Johnston, Curtis Paul Clausen, Elmer Ottis Wooton, Floyd Franklin Smith, Fred W. Miller, Harvey Leroy Westover, Howard E. Middleton, Irvin Cecil Brown, Irvine Theodore Haig, James Thorp, Lester Henry Reineke, Lyle Thomas Alexander, Millard Peck, Orator Fuller Cook, Ronald Floyd Luxford, Samuel Augustus Jones, V. L. Wildermuth, Walter Chapin Holmes, William Hobson Rowe, William John Nolan, Willis James Nolan, Bernard Frank, Charles W. Culpepper, Clarence Sheldon Slater, Donald Bruce, Edwin Butterworth Mains, Elmer Valentine Walter, Horace Greeley Byers, John Thomas Scanlan, Johnson Thatcher Sarvis, Lorraine Joseph Markwardt, Paul A. Berry, R. R. Graves, Theodore Roosevelt Gardner, Anis Rae Peterson, Kaku Sato, Leroy Moomaw, Paul Axel Clarence Eke, George W. Morgan, John Carl Thysell, M. A. Bell
· 1932
- Theodore Peter Dykstra, Alice Louise Robert, Axel Langvad Andersen, Berten Wendell Allred, Charles Wesley Gantt, Clarence Dinsmore Stein, Claude Kedzie Shedd, F. M. Grant, Franklin Thomas Cowan, Fred Charles Simmons, Howard Wilfred Johnson, I. E. Stokes, John Lewis Creech, L. F. Locke, R. W. Leukel, Robert S. Rummell, Ross Calvin Thompson, Thomas Lotti, Tom Dale, Verne Elbert Davison, William John Reid, William Joseph Sando, William Solomon Porte, Rufus F. Dowdle, Claude Carl Wakeland, Clark E. Holscher, Donald William Chamberlain, Floyd Franklin Smith, Frank P. Cuthbert, Grover F. Brown, Otto H. Coleman, Sears Polydore Doolittle, V. F. Tapke, Walton Monroe Nixon, Walter Oliver Hawley, D. J. Caffrey, Jack L. Dean, Samuel George Lehman
· 1955