I used to live in Alaska. Heidenau K60's will serve you fine and you should be able to use the one tire for a round trip. In both Alaska and Canada they put a chemical on unpaved roads that can be slippery when wet. I think it's purpose is to supress dust and make the surface cohesive. Except for that the unpaved roads are like any well maintained BLM road in your state. To me the idea of switching tires in unnecessary. Dave
Pavement! We don't need no stinkin pavement.