Just got back from a 7 day, 440 mile group cc tour in Montana. We all shared sag duties, so we only rode 375 of that. It was a fairly flat route, only 12,000' of climbing, so we did OK on our tandem. We took a lay day in Butte, which was very interesting. We visited the Berkeley Pit, one of the largest Superfund sites in the country, now a tourist attraction. We also visited the Big Hole Battlefield, where the flight of the non-treaty Nez Perce was ended by the US Army, also very much worth visiting.
Western Montana was beautiful with decent riding. Like most low population areas, only the main roads are paved, but traffic was light and the people were kind and friendly. Missoula-Hamilton-Wisdom-Butte-Drummond-Seeley Lake-Missoula.