Another vote for mules. More sure footed than any horse, and easier to get along with than llamas.

My grandfather told me tales of using a fast mule to sucker city kids out of money back before 1920 when most people still drove a horse everywhere. He said a fast mule would win but the city kids would put up their stabled horses as competition, thinking any horse would beat any mule. The farm kids walked off with the money on those bets.

If you prefer a really unusual option, llamas would do nicely for pack animals in the mountains. Downside of llamas is that they occasionally spit on you.

Richard.

Inflammatory Edit:

If you're dead set on horses, the Nez Pierce bred Appaloosas. They may be the only horses ever bred for your climate. And you can teach any horse to work saddle or pack. Additionally, ignore the BS about horse breeds. Any horse can be registered as a general rule and the rules for registry are pure garbage...read the registry rules for several breeds for an hour and you'll notice immediately that most "purebred" horses, including the "breeds" you mentioned, are usually halfbreed mutts.