The scenery is the star here

If you watch the credits, very carefully, at the end it states that the movie was filmed in the Coconino National Forest and some places in Colorado. The Coconino Forest is in Northern Arizona, probably west of Flagstaff and South of the Grand Canyon. That is probably where much of the scenes around Jane Fonda's ranch house and a lot of the scenes of rounding up cattle were filmed. The one scene, where Richard Farnsworth has gone off too die, and where James Caan is riding up the canyon to find him sure looks like the valleys north of Durango.

That's my take. Awesome movie and spectacular scenery. They don't seem to make them like this anymore.

I noticed that the actors were almost always positioned to the far left or right of the camera, it really emphasized the scenery. Very underrated movie, I think.

Living in western Montana and traveling extensively throughout the northern (U.S.) Rockies, as I watched the mountain-front skyline, I tried to identify the exact location of this film. From the way the grassland met with the lower treelines and the look of vegetation, I began to speculate that "Comes a Horseman" was filmed in southern Idaho. Even some of the mountain peaks were reminiscent of Idaho ranges, though I didn't recognize any of them as such specifically, so I was holding out on any final bets.

So I waited until the end credits ran and was not surprised after all that the producers thanked the U.S. Forest Service for allowing the filming in the Coconino National Forest, which is headquartered in Flagstaff, Arizona.

Another aspect of the film's scenery had me intrigued. Being from the West, where anything east of the Cascades and Sierra Nevada's is technically desert (aka "arid"), I know the growing season is very short, which includes Arizona's northern high country. I could not figure out the timing of this movie's story, since it seems to cover "one season" as the characters repeat a number of times: that means a growing season and roundup together. Roundups happen after the grasses have dried and growing season is long over. Yet it had to be long enough for someone gunshot "in the chest" as the Frank Athern character was, to heal well enough to get back into the saddle and rope and toss yearling cattle...that should take some months, even for a tough young cowboy.

And yet, every scene in this film shows only green grass already long. I'm thinking they must have begun filming early in the growing season, which lasts only about eight weeks maximum, less for the aspen trees to leaf out, before that long grass is dried and brown. The outdoor filming probably lasted only a very few weeks at the most.

Unless the producers used an old trick for some scenes: when "Tenderfoot and Lightfoot" (Clint Eastwood, Jeff Bridges, George Kennedy, Geoffrey Lewis, Gary Busey, directed by Michael Cimino, released in 1974) was filmed in north central Montana, where I was growing up at the time, the filming started late in the season and the green grass was long gone from the hills along the Rocky Mountain Front west of Great Falls. So for a few scenes, which the producers did not want looking so dun and bleak, some hillsides were "dyed" green: that is, painted. And to anyone watching it, you cannot see that it is not natural. Locals (Great Falls, Cascade, Augusta and Choteau, Montana) were amazed and still pass on the story.

The least likely possibility for this seasonal timing problem is that the filming occurred over more than one year, that is, more than one growing season. Considering the costs of movie making and logistics, this would not be the answer.

Short of an eyewitness 'fessing up or a look at the financial bookkeeping entries for the film, I don't suppose there would ever be an answer forthcoming. If Jane Fonda still lived in Montana (evidently she gave that up when she split with Ted Turner, who still owns substantial Montana properties), I could try to bump into her and test her memory on it.

The majority of the exteriors were filmed in the Wet Mountain Valley in and around Westcliff, Colorado during the summer of 1977. In particular, these exteriors include Ellie's house and environs, the cemetery, that one shot of "the town" during the opening credits, and the location of the outdoor dance. I also strongly suspect, but don't know with certainty, that the land that Frank and Billy owned (the location of the sniper incident) and any locations with run down wooden cabins sitting next to stands of aspen and pine were shot in that area.

I factually know the above information since I grew up near this valley and had visited it from time to time during my childhood. I firmly recognize a mountain called Horn Peak in many of the shots. It is a mountain in the Sangre de Cristo range which lines the west side of the valley. Sadly, as further proof, a stuntman was killed during this production. His name was Jim Sheppard. If you look up his name right here on IMDb, you'll see that the date and place of his death is 8/18/77, Westcliff, Colorado.

All of the segments containing forested cattle drives were shot in the San Francisco Peaks area of the Coconino National Forest in Northern Arizona. I doubt that anything containing “cattle on the run” and “trees” were shot at the Colorado location; from a cost-effective production stand point, it just wouldn't make any sense to do the "same thing" twice in two different spots that are several hundred miles apart.

And finally, any windowless interiors (Ewing’s place and the bar) were probably shot on a sound stage. But I’m not certain about the interiors of Ellie’s house. There were too many shots with windows and doorways that clearly showed the exterior environs. So I’m gonna guess that they built a more-or-less functional "house on location," shot everything, and then burned the whole thing to the ground.

I think they did a wonderful job in melding together the Arizona and Colorado locations. Both areas are at similar altitudes (mid to high 7000's) and have similar mid-summer bald peaks containing timberline forests and snowfield patches. Even though I know that some of it was shot in Arizona, the whole film "feels" like Colorado to me. And that’s quite a compliment to the filmmakers, ‘cuz I’m pretty picky when it comes to stuff supposedly depicting Colorado...

I hope this has been helpful!

"Gravity is a harsh mistress." -Tick

Really nice.

Can you fly this plane?
Surely you can't be serious.
I am serious, and don't call me Shirley

Very true. This film is breathtaking visually, but as for the story ... not so much. I imagine I'd appreciate this a lot more seeing it in the theater rather than on video, but outside of the gorgeous cinematography, it's a rather underwhelming film overall. 6/10 stars from me.