I went to Borrego Springs this weekend, and it was pretty good there. It's mostly shallow sand, but some areas have bigger dunes, and some places is dirt. Lots of woops, washes, and berms! We went in a group of like 10 people, and there were only 3-5 other people there at any given time! It was wide open, like nobody there, and great stuff to ride! You can camp, have a bonfire, party it up, and nobody will bother you! Just drive out to wherever you want, set camp, and ride!