Hello, is this currently available on a first-come first-served only?

It has both! Check out is 2pm i believe and check in at 3. If you want a spot I could def go by 3-4. You can also go on recreation.gov and make a reservation. We were there the weekend of fathers day! Good luck

I believe you can reserve spots not positive but when I drove through there they had several sights with reserved signs at them