remember, this is 'lush' for arizona! happy valley is a really nice, out-of-the-way spot for some good car camping, usually the streams are running, and there's a neat waterfall just off the road that cascades down bare rocks below Rincon Peak.
I apologize Jeff, I should know better since I originally grew up in the so. cal area that looked similar to your picture. However instead of streams, we had flood control chanels made out of concrete and you couldn't car camp cause someone would steal your car. ; )