moodfood,
To my kowledge the state park closes/locks the front gate at 9 pm like all other state parks. Why not go to Camp Mack. (1/4 mile further down the road) clean showers, airboat friendly, rv and rental cabins, laundry, pool and more.
We've been there four or five times now and fell in love with the camp and it's atmosphere of good people.
Basketcase