First, a .45 is far from a decent "first choice" for bears, we're not talking black bears now, we're in grizzly country.

Second, people have been backcountry camping big parks like Yellowstone, Glacier, and Denali for years - all populated by large grizzlies - with surprisingly few issues. Having a firearm is certainly a boon to feeling"safe", but it's much more effective to religiously practice bear-proofing your camp. A friend, who's considered on the "fringe" by his fellow park rangers, supports the right to carry in National Parks, but IS concerned that he's going to have to start dealing with wounded bears and wolves "peppered with 9mm slugs" (point being - "inadequate caliber slugs"). And, that those instances will only be fuel for the antis to reverse the original law.

Third, I've seen a reference a few times in RV magazines about the firearms laws in all the states. This looks like the one I've read: http://www.gunlaws.com/travel.htm