The road Camino San Ignacio is inside of Warner Springs city limits, not before or after. That part was confusing.
Also, just a note, there are lots of signs saying no trespassing along the road- they are right next to the first stop sign and in other places. If you go there, you are exempt from these "no trespassing signs" as long as you get a permit at the kiosk.
I made the trip out to Warner Springs this weekend (09/17/2011) with the hope of hiking Hot Springs Mountain, but I was informed at the information kiosk that this hike is closed. The woman there was unsure when it would reopen because a fire that took place in July burned down 1100 acres. If you can find a phone number before making the trip out, I would recommend doing so.