Shirley MacLaine did not get along during the shoot with director Don Siegel, with whom she openly fought.
Shirley MacLaine gets top billing in the credits. This was the last time that Clint Eastwood received anything other than top billing until A Perfect World (1993).
Hogan is wearing the same gun belt and holster that Clint Eastwood wore in the "The Man with No Name" trilogy.
Director Don Siegel said producer Martin Rackin wanted to save every dollar on the shooting of this movie, and they disagreed on many points. According to Siegel, Rackin used totally unknown and cheap Mexican actors instead of well known supporting American ones.