Newton Horace Winchell, 1872-1901
William Harvey Emmons, 1911-1944
Frank Fitch Grout, 1944-1947
George Melvin Schwartz, 1947-1961
Paul K. Sims, 1961-1973
Matt S. Walton, 1973-1986
Priscilla C. Grew, 1986-1993
David L. Southwick, 1993-2002
Harvey Thorleifson, 2003-2023
Anthony C. Runkel (interim director), 2023-