Can you show up at anytime and pay to camp or is there a time frame to check in? I ask because I'm planning a trip there and we would be arriving in the night time on a Friday. Thanks in advance!

You should be fine.

All good if its not a holiday weekend.

Depending how late it is when you get there if it's late at night you can pay the fees the morning after you arrive.

Call in advance to ranger station, they should have a price list and mail drop for credit card or check

You pay in the morning, youll be fine.

The ranger station usually closes around 11 pm. If you get caught on the beach without a pass you will be fined.