John Carpenter originally wrote the script in 1971 for John Wayne. Batjac, Wayne's company, read it in the mid 1970s and hired him to do a rewrite. He did but "never quite found out what was going on there. Maybe Wayne didn't want to do any more Westerns. I worked with Michael Wayne and Tom Kane, and they would do things like take out some of the harder action stuff, making it easier on him."[1]
In the script the John Wayne character was an old riverboat rat who was really a U.S. Marshal searching for some criminals. He met up with another man and they went down the river, like Huckleberry Finn.[1]
"I'd love to have had Hawks direct it but Hawks was too old," said Carpenter. "I would love to have directed it, but I don't think they would have let me."[1]