We've stopped for quick overnights on Arizona Trust land a couple of times without getting a permit, risking a fine, but since we planned to stay at this site for several days we decided we better do it legally. The permit is easy to get by applying online, then either printing out the receipt or saving a photo of it.
The RC Airstrip was originally the Catalina Mountain School, a boy's juvenile correctional school, that was in operation from 1967 until 2011 when the boys were transferred to other facilities. All of the buildings were removed leaving parking lots, foundation slabs, roads, and large trees intact. This gives campers an option of places to park. There's a large paved lot near the entrance and a large dirt lot a little farther in. The slabs vary in size from room for one vehicle to large enough for a group. There are also spots under the trees if you want shade. The roads around the slabs are in fairly good condition but the outer edge roads have some rough patches. Walk them first to be safe. The entire area is about 200 acres so there's plenty of room for everyone.
We really liked this spot for the beautiful scenery and the roads that made good walking/rolling trails. It's also very clean and quiet except for the traffic noise from Oracle Road. Grocery stores, Home Depot, Walmart, a free dump station and fresh water, and almost anything else that could be needed or wanted is within ten miles. We camped in the dirt lot. If you chose that location, park along the long sides and leave the ends open for the old guys that come every Sunday, Tuesday, and Thursday morning to fly their remote control planes. The trust land is also used by horseback riders, walkers, and occasionally kids on dirt bikes and ATVs. Camping 32.47014, -110.92091