From I-35, take Exit #55 and drive towards the city of Davis, OK. Once in Davis , go east on Highway 7 to the Chickasaw National Recreation Area you desire. Watch for Chickasaw National Recreation Area signs to direct you to your selected area. For Rock Creek or Veterans Lake Pavilion continue west, cross the low water crossing, and follow the signs.
The area is nice but $20 a night to tent camp? Ah no. Plus the entire southern area is closed. Don't know why.
Rock creek campground is awesome, been going since I was a kid. Its nestled between the creek and Bromide "hill" close enough to wall then hike the hill to the overlook, a short walk to veterans lake, a little drive away is Travertine creek, little Niagara and the travertine nature center.
Restrooms are clean and centered on the loops. Only downside there is sometimes other campgrounds may have to walk through yours to get to them but that's the price to pay for a site next to them
Campgrounds 40 and higher are the best but are only open in season (or as needed?)
Plus its 2 minutes to town if you forget any camping stuff.