A state park with FULL Hook-ups!  Cuivre River state park is a nice hidden treasure for a weekend getaway from St. Louis.  Great trails to hike and a sandy beach to dip in for a quick swim.  Did I mention full hook-ups in a state park.  It would make a great return place for a weekend in the fall to see the colors as the trees turn.  I would highly suggest getting a screen house to enjoy the evenings outdoors to keep the gnats and mosquitos away.