Wayne is driving his cattle to Belle Fourche and it looks like he started out somewhere in Montana. That part is not explained very well and is probably a remnant from the original story that was left in. Belle Fourche is a nice little town just north of the Black Hills and was the site of one of the Wild Bunch's bank robberies. Other than that it was a ranching center and transportation hub for the gold mining camps, like Deadwood, in the Black Hills.
shareNear the beginning of the movie, the cowhands rode in from Bozeman, MT the night before so you can assume that was the approximate starting point for the drive. They also pass by Little Big Horn on the cattle drive. Custer was killed in 1876 years after the movie, I think the movie was set in 1872 so the comments in the story must have been a foretelling rather than historic. The Bozeman gold rush referred to as being over was in the 1860's.
I overnighted in Belle Fourche once, just to say I was at the geographical centre of the US and I also stayed in Rugby, ND (centre of NA).
Anderson told Nightlinger that his oldest boy would have been near 40 and his oldest was born in 1836, so it was somewhere around 1876 when the movie takes place. The remains at the Little Big Horn hadn't been buried yet, so it was close.
I spend my money on dope, sex and cheap thrills.
The rest of it, I waste.