No they are not on Marina Drive anymore, they are on S22 and Holly Rd. The last time you were there the land was still privately owned but has been handed over to the BLM and they manage use now. The 1st couple years they moved the entire event to Superstition but have recently gone back to the Truckhaven location but the camp is now off the highway.
Here's the directions through our clubs bb...
http://spinnin4s.50.forumer.com/thermal-truckhaven-alternate-t450417.html