Campgrounds south of Oklahoma City

We stayed twice in Norman, Ok (just south of OK city). this winter going and coming back from Texas. It was the River Wind casino right by I-35. I called them and asked if there was RV parking and they were enthusiastic about having us and said there was a big buffet breakfast and the shuttle would pick us up and take us to the door and back with 24 security. Very nice people and the security parked with in 300' of us all night. Best of all it was free so we felt compelled to at least have the breakfast. I'd stay there anytime!