Travel a few miles down Brush Creek Trail. After passing Strand Hill MTB trail you will get to a split in the road. The left turn will take you up a deeply rutted 4WD road towards Teocalli Ridge MTB trail. Lots of beautiful camping on this road. But it can be tough sledding when it is wet. If you stay to the right you will get to a flat where many people will camp. You can get a smaller RV/Trailer/Sprinter here very easily. If you are intrepid - and have a good 4WD with some clearance - you can continue through the creek and up the hill where superb, quiet dispersed camping exists. 

Leave no trace.