It says no camp reservations but open to camping. Are my chances good if I just show up and hope to get a campsite??

As of Sept 1st the sites are first come first serve. They still had open sites late yesterday afternoon.

I agree, you need to make reservation.

Absolutely not, sorry! When we were there they had no walk in sites & someone tried to take a "free" spot & got kicked out.

We were just there and we booked months in advance and they were packed! I would definitely suggest calling them first. Hope that helps