Miller Fort-William-on-the-Laramie-sj Alfred Jacob Miller

The picture has something of this: people, group, cavalry, mammal, desert, camel, seated, vehicle, many, outdoors, herder, transportation system, man, landscape, livestock, dawn.
Perhaps it’s a painting of a group of people riding horses in front of a white building with a flag on top of it and a flag pole in the foreground.