I don’t really know. These have an easy link to those in the Thompson Falls area going across the Koo Koo Sint Ridge and are probably related to those to the east of Plains and those over in the Patrick’s Knob area. We’re a long ways from the Bull River though so there may be a division there.
When I saw the pronghorn in western Kansas, I noted their white rumps. I’ve never noticed the white rumps on bighorn sheep, probably because their horns are so impressive and their faces so expressive. But now, I’m wondering. Is there some purpose to the white patches? It’s interesting that the pronghorn and sheep both have them.
Elk and mule deer also have the white rump patch. Even my unsophisticated eye can pick out those white rumps at a great distance and at the same time distinguish the species from it, and so I think it may be a means of visual communication for them.