A couple of years ago we were heading back to MD area from Glacier National Park and stopped at Mirror Lake State Park for a couple of days to layover. We really liked the park - the site we got was huge and had electric hookups.
We are in our mid-40's, no kids. We enjoyed walking around the town and checking things out. We got some great cheese, had a couple of decent meals, and did some window shopping.
We wanted to do a boat tour or a canyon tour but, since we hadn't planned on being there, we had no reservations and everything was booked. We will probably end up back there again. It is kitschy enough to be amusing and not as crowded as Gatlinburg.