I really like my Kelty Redwing backpack.
http://www.google.com/products/catalog?q=kelty+redwing+backpack&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=UTF-8&tbm=shop&cid=1731160766756873620&sa=X&ei=PXwQTpWEMI-KhQe0vMjqDQ&ved=0CG4Q8wIwAw

Big enough for a 3-day bag, actually rides well, I think it's well organized and reasonable at about $60. One of my medics uses that Molle 3 and it seems OK, but maybe a smidge small. Then again, I tend to pack a bit...

If you're planning a trip up to AK, check out expeditionportal.com Probably better suited in some ways to your trip; there are several after action reports on people driving through the state.