Three Forks, MT to see where the Jefferson, Madison, and Gallatin Rivers converge to form the Missouri River. Also, a side trip up to Great Falls, MT to see the Lewis & Clark interpretive center....well worth the visit. Also in Great Falls is the Charley Russell museum featuring his western art. In Missoula, MT is the Smokejumpers center that offers tours. Their is the silver dollar saloon right before entering Idaho for a quick break and right next door is a forest service nursery. Exit 62 & 61 is the town of Wallace, Idaho that you might enjoy just driving through.