When are you guys heading out? And are you riding all the way or, God forbid, trailering part of the way? Fly and Ride? How many days are you riding, and how far are you comfortable riding each day? And finally, how picky are you on your accomodations at night?
We are doing about the same ride in late May, early June. Three bikes leaving for western Ark, one coming up from New Braunfels, two from Lubbock. Meeting up in Las Vegas, NM, then heading up thru central Colorado, kicking over into northeastern UT and Flaming Gorge, then up to Pinedale, WY and into Jellystone from the south. Looking at doing some roads in Idaho, but looks like there are plenty of good roads around southwestern MT. It depends on how tired the guys are after the ride out, but I got some good route planning info on the PNW link on this forum for some Idaho roads.
You almost HAVE to do Bear Tooth Pass. Again, depends on time, but Glacier is awesome. I also enjoyed Devils Tower and Custer Battlefield (not so much the road at Custer, but the history)...
We've stayed in Marriotts, and Larriotts (there's a story there, $9 a night per person). As long as the sheets are clean, we're in!