Lots of state trust and forest service land in southern AZ for boondocking. Agree with the Chiricahuas recommendation and your rv would fit in the National Monument campground. Another favorite for us is Sunny Flat campground near Portal on the east side of the Chiricahuas. Lots of forest roads for 4-wheeling. The east side will be a bit cooler though. Lots of places closer to Tucson on the Coronado National Forest for boondocking and 4-wheeling. The desert is full of all kinds of roads going to cool places for exploring.
