DUDE! Montana rules. Has to be summer or fall, though. Here's a couple of quick ideas to get you started, the first one is too long for 2 weeks, but you could chop off the northern loop or travel one-way from Bozeman to St. Mary or so, and get home some motorized way.
http://maps.google.com/maps?saddr=N+...,11,15&t=m&z=6
http://maps.google.com/maps?saddr=I-...ia=1,2&t=m&z=8