Not being a biker, I went to ground to see if I could dig up some info for your trip. One site that has some useful info and suggested itineraries is YellowstonePark.com (http://www.yellowstonepark.com/PlanYourTrip/Map.aspx). Also, have you heard of a map company called MadMaps? They started out as a biker-focused mapping service, using local bikers as their on-the-scene sources, so their recommendations are totally tailored toward bike touring. Check out their MT/WY maps at: http://www.madmaps.com/roadtrips/products/view/1026/. (I've worked with Mad Maps for some content on Away.com and they're a good crowd; very passionate about putting the rubber to the road!)