It's just too hot and dry to camp here in the summer. Many of the campsites at Joshua Tree are cleverly hidden among granite outcrops. Open desert camping means no facilities, no neighbours, and is allowed in many places. The national park service decided to allow vehicle camping along this mile-long stretch of the Redwood Highway. Tent camping is the simplest and cheapest way to go, and gets you closest to nature.
Some people take along everything when they go camping.
Every few years the level of Lake Elsinore rises and the state park campground goes under. In the rainy climate of the Olympic Peninsula a roofed campsite can be extremely welcome. They wouldn't make all these rules if people hadn't tried to do all these things.