Universal Pictures wanted this movie to be shot on the studio lot. Instead, Clint Eastwood had a whole town built in the desert near Mono Lake in the California Sierras. Many of the buildings were complete and three-dimensional, so that interiors could be shot on-location.
Shortly after this movie's release, Clint Eastwood wrote to John Wayne, suggesting that they make a western together. Wayne sent back an angry letter in reply, in which he denounced this movie for its violence and revisionist portrayal of the Old West. Eastwood did not bother to answer his criticisms, and consequently they did not work together.
This movie came in under budget and two days ahead of schedule. Clint Eastwood is famous for being an extremely efficient director.
The town of Lago was built 300 miles away from Hollywood. A 46-man crew of technicians and ten laborers worked ten hours a day for eighteen days constructing fourteen houses and a two-story hotel. They were burned down at this movie's completion.