Allan William Colt MacDonald (December 2, 1891 – March 27, 1968), who used the pen name William Colt MacDonald, was an American writer of western fiction born in Detroit, Michigan whose work appeared both in books and on film.

His many novels included Gun Country (1929), Rustler's Paradise (1932), The Crimson Quirt (1949), Action at Arcanum (1958), and California Gunman (1957).^[1]

His film credits, all for character writing, are about his most famous ones, The Three Mesquiteers−Stony Brooke, Tucson Smith and Lullaby Joslin. They first appeared together^[2] in the 1933 novel Law of the Forty-Fives.

The novel was adapted into a movie in 1935, The Law of the 45's, by the independent producers Arthur Alexander and Max Alexander. It featured only two of the characters: Stony Brooke played by Al St. John and called Stoney Martin, and Tucson Smith played by Guinn 'Big Boy' Williams. In Powdersmoke Range, another novel adaptation shot in the same year for RKO, the three appeared together. Stony Brooke is played by Hoot Gibson, Tucson Smith by Harry Carey, and Lullaby Joslin by 'Big Boy' Williams.

Between 1936 and 1943, Republic Pictures released a Three Mesquiteers film series, starting with The Three Mesquiteers, with Robert Livingston as Stony Brooke, Ray Corrigan as Tucson Smith, and Syd Saylor as Lullaby Joslin. Among the 51 movies of the series, 8 have John Wayne as Stony Brooke : Pals of the Saddle, Overland Stage Raiders, Santa Fe Stampede and Red River Range in 1938, and The Night Riders, Three Texas Steers, Wyoming Outlaw and New Frontier in 1939.

• Works by or about William Colt MacDonald at the Internet Archive
• William Colt MacDonald at IMDb