Do visitors have to be out by 5 since the park closes at 5, or just the entry gates close at 5?

Yeah the visitor center and gift shop close around 5. As do the main bathrooms there. We stayed til about 7 just recently which was nice.

Entry closes at 5

Gates close at 5:30 for entry but you can stay in park later "as long as you want". Last shuttle down at 5:35 but you can walk down after that.