Burt Lancaster had met Ossie Davis on the historic Martin Luther King "Civil Rights March on Washington" on Aug. 28, 1963. This chance meeting led to the talented Davis being cast as "Joseph Winfield Lee", the runaway slave who uses his clever, resourceful ways to manipulate fur trapper "Joe Bass" (Lancaster) in the film. Lancaster also stated that first time screenwriter William W. Norton submitted such a unique, clever script, that he just had to do the film.
Burt Lancaster first met Sydney Pollack when Pollack worked as a dialogue director on the Luchino Visconti epic O Leopardo (1963), in which Lancaster starred. This was the second of three movies that they made together in quick succession., the others being Enigma de uma Vida (1968) and A Defesa do Castelo (1969). This was by far the most successful of the three.
In his review for the film, a critic remarked that Burt Lancaster's performances had not varied much over the years, unlike his hairstyles.
Filmed in Arizona and Mexico.