I want to plan a road trip here although my friend is 17 and we’re traveling with our parents. Will she be allowed in the den if she has a permission slip with parent signature and notarization?

She will need a slip. Im pretty sure but your perants might be able do it for her i would call there office

Parents have to sign a waiver for minors. Everyone has to sign a waiver to be on site anywhere except the office. You get a wrist band after signing the waiver. They are quite strict about it. Without the proper wrist band you are not going to able to hang out above the den either.