The sites are elbow to elbow with small trees in between. No campfires or picnic tables because of past problems with bear activity. Those are the bad points. The rest is all good. The campground was quiet even when fully packed for the 4th of July holiday. There were lots of children and pets and people were polite and friendly. The campground is a good central location for touring the park and we didn't have any trouble with electrical power or water. The water pressure is high so make sure you take a pressure regulator.
We stopped for an overnight on the way back from Wyoming and got the last site with full hook-ups. The sites were typical KOA, close quarters, but the park was well laid out and the WiFi worked well. Use virus and internet security, because I was attacked by a trojan within moments of logging on. The nightly shuttle to the Mt. Rushmore lighting apparently books up very early, but there are rental cars on property and it was quick and easy to rent. The pools were clean and busy and people sat quietly by their fires after quiet hours with no loud noises after quiet time at 10 p.m.. We would stop here again for an overnight but it is too big and crowded for a long stay.