We do most of our RV travel in the early spring and late fall.  Ferne Clyffe does not take reservations after November 1, so its first come first served.  Payment is deposited in a kiosk near the black water dump site.  This was not well explained on the signage or websites, but, at least in mid-November, there were enough experienced campers around to explain things. 

Otherwise, Ferne Clyffe is gorgeous. Great for star-gazing. Lots of mature oak and sycamore trees that I'm sure provide nice shade in summer.  In mid-November, there's lots of deer hunters, which means it gets quiet early in the evening.  Spaces are of moderate size on the interior, and are more spread out on the perimteter.