I'm currently in the primitive camping area in a tent next to my vehicle. I have not seen any signs about cost or payment, but I got in late last night, around 10pm on Saturday night in mid-October. The RV sites looked pretty full, but there was plenty of space in this primitive area which is next to the RV sites. I did not see any numbers or designated parking spaces, so I just sort of guessed. So far, no issues.
Update: In the morning, a man in a golf cart drives around. He collected $10 from me and gave me the code for the bathrooms/showers. The showers are nicer than expected, but not fancy.
There are some endangered birds in cages outside the showers. Check out the owl and the hawk!