I would have to say the 480. I've heard of people taking the African 'dangerous5' with a 460S&W. Plus the 460 is versatile, shoot 460 or 45, or 454 Casull.
Enjoy your trip!! My first solo backpacking trip was in the Bob Marshall. I was 13 and just had a Ruger Blackhawk 357. In case of a grizzly problem, my plan was to fire all 6 shots, throw the gun at it, drop my pack, and haul ***! My Grandfather dropped me off in the mtns east of Big Fork, picked me up 10 days later on the Hungry Horse side at a pre-arranged spot. But after 10 days and nearly 40 miles, I never saw one, (lots of sign though). Of course I wear a bell on my pack when in bear country (they don't want to see us either) but that's not an option when hunting.
Sigh.... I miss Montana.