Worry about other hunters in this situation? Any hunters for miles around are going to be more than evident, with their blaze orange and vehicles!
Your assumption on my part is most correct. I have never been hunting on horseback in the mountains and you may be correct in your assessment but what about non-hunters (hikers, campers or maybe people living up in the mountains) that may not be wearing hunter orange? Maybe I'm missing something but sweeping a mountain ridge or getting a better view of movement with a scoped rifle on a mountain ridge would seem to me to be no different then doing it anywhere else.