Sands Point Preserve closing time? (Nassau: permit, county, summer)

[JDong217]

Their website says it closes at 4:30 PM, but does that mean everyone has to be out of the preserve by 4:30 or that no new entries are permitted by 4:30?

I've been there once before in the summer and I could've sworn I was in there way past 4:30 but my memory is really hazy.

I'm going with a friend an he actually works at another preserve in Nassau county so he was going to ask if we'd be allowed to stay later but I'm not sure if it's going to be an issue.