There are some first come sites, but when we were there, I don't believe they were taking reservations because the campground was technically closed for the season. A ranger told us we could camp there, and we weren't alone.

When we went We reserved our campsites.

Reservations can be made 6 months in advance for the peak season only, May 24th through September 10th. Off season is first come - first serve only. I hope this is helpful to you.

They have some FCFS sites and you can also make reservations through recreation.gov. I just pulled in one day and they had lots of sites so i checked with the camp host and it was super easy. It's a wonderful little no frills campground.