Spent earth day here in 2018 - it was perfect. We actually pitched our tent in what is known as Workman Creek - just a little further up the road. Definitely recommend a higher clearances vehicle, although I made it okay in my standard Ford Escape. Workman Creek is a great dispersed camping location and the views from the top of the mountain are unmatched. Careful of fire restrictions in dry season.
It was a nice little spot not too busy or difficult to get to. We were the only ones there. Falling asleep to the sound of the creek was nice but road noise was a little too close.
One of the few places to car camp with a lake in Tucson! Wife and I had a wonderful weekend here in October. The lots are huge, have big food boxes/bear boxes and the hosts are super kind. I could have done without the annoying drunk late night yellers, but a lovely place nonetheless.