Good Question
There are several good breeds I feel comfortable useing in the mountains. Quarter horse, Thourobread and Arabs are some that I have used. I dont think the breed is as important as the horses behavior. You need a horse that you can trust and that does not get excited over little things. The only way to accomplish that is to spend many hours in the mountains with you horse. My last elk hunt we packed in 12 miles ranging from 9000 to 11000 feet. My horses were used to the country so we had no problems. If you are new to horses I recomend finding a friend that knows a little about them. Hope this helps. If you want more info just ask.
Stay safe

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