Trivia

Only actor aside from John Wayne to appear in all three Howard Hawks western trilogy Rio Bravo 1957 (uncredited), El Dorado 1966 (Milt) and Rio Lobo 1970 (Whitey Connor).

Appeared in costume as his Mork and Mindy character, Exidor, on an episode of Password Plus in 1981, alongside Jon "Bowser" Bauman of Sha Na Na and Patty Duke.

Had no children.

Upon Donner's death, his body was cremated, with his ashes given to his wife.

Lived in the Los Angeles neighborhood of Sherman Oaks for several years.