Can't be over-emphasized, IMO. During my group trip we had a day off in a town with more than that (Glasgow, MT) and it was God-awful boring. The highlight of the day was the customer appreciation BBQ at the local grocery store. We also had a few other short, flat days in Montana that left us with a lot of hours to fill in towns with nothing to them. Best rest days were Glacier NP, Lake Itasca SP, Minneapolis and Niagara Falls, ON. Lots to do and see.