Are you available to leave after they leave the check in office? And how would one get back in the park after hours?

They give you a gate code to use after hours

Yes, you can leave anytime and return after office closes. You are issued a gate code. Quiet time is 10 pm to 7 am. So if you come in after then be quiet...lol

Gate code on your receipt allows 24hr access.

Yes you have a gate code & can come & go after hours