Duvall, 75, was upset by changes in the two-part "Broken Trail" script last August that focused on unwarranted "gunfights" and other melodramatic devices, he said.
"I said to AMC, the head guys, I said, 'I'm out of here," Duvall said. He wanted it to go back to the original text written by screenwriter Alan Geoffrion.
Rewrites began right away and, from that point on, production went smoothly. Filming took place Aug. 15 through Oct. 18, 2005 in the Canadian Rockies, about an hour from Calgary, Alberta.
"We were on the right track," Duvall said.
Duvall plays a rancher going on his final drive in the 1890s. Thomas Haden Church, who also played in "Sideways," is featured as Duvall's nephew who helps herd horses from Oregon to Wyoming.
"Broken Trail," which was directed by Walter Hill, airs next Sunday and Monday nights on AMC at 8 p.m.