All sites are first come-first served (no reservations). But given the remoteness of the park, there were open sites all week.  Most sites are separated by trees, creating a back-country feel (as opposed to a crowded Nat'l Park).  There is a nice creek along one side, enhancing the camping experience.  The whole site is spacious.  The picnic tables are smooth concrete, not splintered wood.  The tent area is flat and level.  The bathroom vaults are the cleanest I've ever encountered.  Overall, the perfect setting for a great week.