George C. Scott Dan Logan Director, Actor Richard Basehart Dr. Roy Caldwell Actor Martin Sheen Maj. Holliford Actor Barnard Hughes Dr. Spencer Actor Nicolas Beauvy Chris Logan Actor Paul Stevens Col. William Franklin Actor Stephen Young Maj. Reintz Actor Kenneth Tobey Col. Alan A. Nickerson Actor Robert Walden Dr. Tom Janeway Actor William Jordan Maj. Coopr Actor Dabbs Greer Dr. Thompson Actor John Dierkes Bill Parker Actor Bette Henritze Sarah Parker Actor Lou Frizzell J.T. `'Spike'` Boynton Actor Ed Lauter Simpson Actor Terry Wilson Kaufman Trucking Co. driver Actor Fielding Greaves Dr. Walter Steenrod Actor Fred Weintraub Producer