I did try to camp at Cottonwood Springs, South entrance, but all 55 available sites were taken (loop b was closed and locked with a swinging gate).
I left, heading North into the wilderness....somewhere around Smoke Tree Wash I found a pull out, parked by myself and threw my sleeping pad on the ground. Laying there, letting the desert air carcass my skin I had no worries...I feel asleep without a concern of the snakes or scorpions or whatever....just me and the ground and a lovely breeze with many blazing fireballs in the sky above.
Temp was low 80's.
I did try secure a camp site Jumbo Rocks at about 4:30am but again, all 100 or so sites were taken.
Camping is good...but for this trip....there were too many people in these rugged landscapes, all crowded together...nice people, but alone was better.
I have a lifetime pass to the national parks...best $10 dollars I ever spent. (but you have to be over 62 young man!