I was in search for the same thing I ended up finding out about Riverside County Ordinance 514 from a Ranger who confronted me just to check out my weapons.
This is an old thread but the map seems still valid:
http://www.calguns.net/calgunforum/s...d.php?t=388656
Thiers two places I go 1 off highland springs rd. All the way south a lot of dirt bike riders though and 1 off San Gorgonial Rd south then vear right to Old Idyllwild Rd. PM me for some coordinates, I also take 2 50 gal trash cans and spend a few hours cleaning up as I lay my steel targets.
I've read a few forms here about a place in Perris also that does clean ups also if anyone has details please chime in I'd love to help
I know a lot of people will get upset over exposing shooting spots because they get trashed. In my opinion they will get found simply using Google and Google earth. We can only contribute to clean up after the other ignorants. I choose to lead by example instead of complain