There is only one South Campground at Zion NP
You can check out my other reviews for Zion National Park. Make sure you don't get confused, there is only one south campground at Zion National Park. If you are looking for long term reservations then you need to camp at Watchman. if you can take the risk of a first come first serve campsite and you have missed your window for getting a site at Watchman, then take your chances, it is worth it. But get there early, before 7:00 a.m. The campground fills up quickly.
Zion is becoming more poular every year. Expect big crowds.