There's German Shepherd Rescue of Orange County. You could Google to see if there's another one. GSD rescues are, unfortunately, very common. Search German Shepherd Rescue, not German Shepherd shelter though- that should help.
ADCH Mikko (USDAA) SCH-B; (NADAC) EAC, EJC, TN-E, TG-E, VerO; (AKC) NAJ, CGC; (NACSW) NW1 - 9 year old GSD