oldtrojan66 has offered some sage advice.
icanon wrote:
I read somewhere about people being attacked by wild animals at night while letting their pet relieve themselves nearby.
I have heard rumor of small dogs being captured by coyote's at Quartzsite years ago when their owners let them out to do their business at night, but I've never met anyone it actually happened to.
This article may help with your quest for information. It talks about where you can camp and how to find boondocking spots, links to US Forest Service online MUVMs (motor vehicle use maps), and the only official dispersed camping rules put out by the USFS I've seen...
http://www.rv-camping.org/boondocking/