The park itself closes at 9pm so I advise getting there before then. If they happen to notice you without the paper that hangs from your rearview mirror you can get in some trouble.
They have self check-in if nobody is the gatehouse to check you in. It's a great place to enjoy.
If you arrive after they have left the gatehouse, they leave a paper up in the window with the names and sites of people still set to check in.
I don't know. I got there around 5pm. No problem.
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