I love AK, and I love Fairbanks. AK is the only place where you go where you can just feel how it could will kill you. =D It is so hard to explain to people. I wondered around there for a bit a few years go, never bike riding, but I would think that Alaska is one of the more interesting places you could mountain bike. I can't imagine it is pristine there, probably hard core, so I wouldn't worry about it. Once you do it for a while, you will be an expert and all other trails won't compare.