Over the years, we overnighted at a police station (with their permission), a truck scale off an interstate, just off an off ramp one New Year's, on the Sioux Indian reservation (with permission), and all the usual free overnight dry camp spots (schools, church's, hospitals, Walmarts, Cabelas, etc.).
Once, when I was young and had a little black p/u with a black camper, I snuck into the back of a picnic spot at Yosemite and had the place to myself while all the other poor slobs were crammed into the campgrounds (height of summer). I was probably lucky to get away with it.
Oh, almost forgot, about 10 years ago, I had my trck camper and was at Bryce. As an amateur astronomer and member of my local club, I had my telescope with me and saw they were doing an astronomy program that evening. I spoke to the rangers and offered my scope to the mix. My only request was they let me overnight at Bryce Point as it would be 1 or so AM before we packed it in. They had no problem with that and I had the spot all to myself until sunrise. It was great!
2001 GMC EC 2500HD, 4x4, 6.0 V8
2002 Pleasure-Way Traverse
2002 Lexus Land Cruiser (LX470)