Franco Nero had a broken hand throughout the film because he actually broke his hand while punching a misbehaving horse on the set of Keoma - Melodie des Sterbens (1976). Because of the injury the script was rewritten to have Walter drunkenly fall and break his hand early in the film. It was also rewritten so that Eve would be driving the car throughout the film. Originally it was supposed to be Walter driving.
The film was intended to be set in northern California, but the budget wouldn't allow the film to be shot outside of Italy. The filming locations of L'Aquila, Italy were chosen because the terrain looked like the American west and the road signs and gas stations were made to look 'Americanized'. This sometimes confused American tourists whenever they came across the shooting locations and found everything written in English.
During an interview star David Hess said that co-star Franco Nero broke his nose while shooting a fight sequence.
Star Franco Nero suggested David Hess for the role of Adam because Nero had recently worked with Hess for the film Die 21 Stunden von München (1976). While shooting that film the two met and Hess told Nero he was anxious to work in Italy.