I stayed at Coral Pink Sand Dunes State Park for a few nights last year and loved it so much that I came back with a friend for a few nights. The campground itself is awesome. Each site has a picnic table, grill, fire pit, good parking, trees, and a water pump nearby. The bathrooms are nice (real plumbing) and the showers are heavenly after days on the road without a way to bathe. Love the sand dunes as well. All of the campsites are with in a reasonable distance to the bathrooms and the stars are amazing here. 

This is an awesome place to stay if you want to be close to both Bryce and Zion National Parks. Only downside is that there is absolutely NO cell signal. Great place to get away from everything, but if you're trying to be in contact with the outside world this is not the place to do it.