This question excludes NON-Operating Parks (because they obviously lack gatekeepers) that I deselected in the map.
My overly anxious grandparents (of age 77 and 75) prefer visiting and camping at Operating Parks (henceforth OOP) that are monitored and have gatekeepers. But the linked map above fails to communicate this: at some OOP (found with that link, but whose name they forgot), they discovered no gatekeeper; instead the gate was open and a donation box was left instead.