Stockade South is a Quiet, small campground. Smaller campers and tents only in this campground. It's underrated in my opinion - we drove through other Custer campgrounds and preferred ours. Clean bathrooms, very nice hosts, spacious sites. We had site 2 and it was one of the best (if you come prepared with leveling blocks), with plenty of trees and room to play. Close proximity to the rest of the park, hiking, and many SD attractions. Only drawback is no dump station - there is only 1 in all of Custer.
The good: swim beach is not right in campground but nearby. $3 entry for beach. The RV campground is on the water, book far enough in advance for a waterfront site. You can kayak or fish from campground. Sites all seemed flat (meant for RVs but most had grass good for tent setup) and most were shady. There's a playground by bathrooms which have showers. Showers were a good temp. Campground was not particularly loud when we were there (even on a holiday weekend).
The bad: bathrooms seemed dirty even for campground bathrooms & 1 stall was broken, leaving 3 showers & 2 flush toilets for the whole campground. Sites could have been a little more spaced out/ private.
We live 20 minutes from Moraine view so I'm sure we'll be back. :)