Thanks for the campground info and links!
Drycamping in the desert is no problem for us (we're rockhounds). However having to make reservations for that campground sure takes some of the spontaneity away ... which is a bummer way out there as to you can't estimate how many days you might want to stay until you get out there and wind up having more fun than you thought you would.
Once you're out there in that campground and your reservation(s) run out, do you automatically have first dibs at signing up for more days - locally at the campground (using an iron ranger) - to extend the time in your campsite that you originally reserved?