I wasn't able to go to this Zone Trip. It was held at Slab City near Salton Sea in Southern California - 33°15′32″ N, 115°27′59″ W. They had a theme - Post-Apocalypse - Punk. It looks like it was organized by an urban bicycling group called the Midnite Ridazz along with some So Cal Cacophony Society people. As near as I can tell, about 40 people turned up for a weekend campout. They visited some of the interesting sites at the Slabs - Salvation Mountain, The Lizard Tree Library, The Range, and East Jesus.
On another subject, pictures of Zone Trip #1 show up also as Zone Trip #7. Apparently there is someone keeping track of the actual sequence of Zone Trips, wherever they occur.