I ride that area on the north of Shadow Mtn Rd (north of El Mirage) with Darrell Moore a lot (Hi Vista generically). From there all the way to the Edwards fence line, East to 395, across 395 then north to Kramer Junction or south back to the trucks. Lots of great non-whooped trails. There is a little or never used official staging area at about 240st east and ave G. I'll have to check it on goggle. We ride past it and have never seen a vehicle there.