We stayed at the Midway Campground inside the preserve. The campground is run by the National Park System and is one of several in the park, but the only one with electric hook-ups.
Value - 10 - We paid $10 a night for a back-in black-top site with electric only. Dump station on site is free to campers. Rate was with National Parks Pass discount - normally it is $19.
Bathrooms - 6 - Modern and clean, but no showers.
Roominess - 8 - Plenty of room for our rig, tow dolly and van.
Facility fun - 5 - Not a lot to do in the campground, but plenty of trails and exploring in the park itself. Our boys enjoyed finding various types of bugs while playing Legos.
Facility usefulness - 5 - Dump, picnic shelters, fresh water fill-up.
Overall - 9 - The park is super clean, super cheap and very serene.