Close to the park but basic campsites
We spent one night here so we could go to the park. Nice enough campground with level spaces and full hook ups. We paid $54. Area also has cabins and a lodge as well as a store with a little restaurant. The showers were amazing at this place. Nice hot copious amounts of water and very clean. About 4 miles from the park entrance. Sandunes were pretty cool, but unless you want to hike to the very top of them, you could easily only spend two hours at the most here. 
Site16
Month of VisitAugust