Cottonwood is the furthest south campground in the park, and was the only camp that had space. It's extremely clean and spacious. There are hiking trails just off the campground. The restrooms don't have showers or lights.
The north campground is amazing, just a short distance from rim. We were there in early April, only Loop A was open. Most of the sites are huge, but they have enough so there's a chance you'll get one that will fit in. The Restrooms are clean, but they have no showers. Amazing views, nice and quiet. There's a camp store thats a short walk away and is well equipped. It's not far from town so if you need other things it's an easy trip.
This State Park has a great camping area. It has places from tents to full hook ups. The restrooms were clean and had showers, but you had to pay for time with quarters, and there's a change machine so you can get quarters.