We were hoping to stay at the Gila Hot Springs campground, but it was full. Although the hot springs were oh so tempting, we're glad it turned out that way. First, FREE! Second, fabulous views, stars, and amazing quiet.
All along Route 15 in the mountains to the south of Gila Hot Springs are numerous pull-offs, pull-outs, and pull-throughs where you can camp overnight. I wouldn't recommend a long stay, but we found a little road off up a gentle embankment with a killer view. There were many others we would have gladly stayed at too. We are pulling a 17-ft travel trailer but some of the spots are wide and broad and would fit a much larger rig.
No-one but a masochist would drive along Route 15 at night (slow, steep, winding) and so there was zero car noise all night. This would be true for any of the pullouts, so even though you're close to the road, there aren't any cars so it doesn't matter much. No cell service, but there isn't cell service anywhere in the area, even in Gila Hot Springs.
We drove to the cliff dwellings in the morning, took a leisurely 20-30 minutes.