Cuivre River State Park, Troy Missouri was a real surprise. We went last year in the fall and had a great time. The park is very nice, the full hookup area was beautiful and the prices for camping in Missouri State Parks is very low. We have planned another trip to Cuivre River this year.
I live about 15 minutes from the park. We LOVE it. It's not well known, MOSTLY locals, and it's kind of hidden away, so you feel further from "town" than you are.