That Ocotillo area is an interesting place. So many boulders! It would be easy to get lost up there, especially when it’s one of those hot days in August. The book sounds REALLY interesting. I hope I can get the library to order it. I imagine they can get it somewhere. Amazon has it too, for $20.
The cave with the guns, is west of Ocotillo and south of the
I-8 freeway, in the foothills.
That is also on the San Andreas earthquake fault, so there is no doubt that the boulders have moved in a hundred years to hide a cave.