Griswold Hills is out there too. Maybe a LITTLE bit closer but not much, not sure on that, never actually checked the mileage...
To get there you stay on Panoche Road (heading towards the abandoned mining town of New Idria) instead of making the left turn onto Little Panoche Road (which takes you to Panoche and Tumey shooting areas).
Downside to Griswold is that it's a MUCH smaller area to shoot in compared to the other two, better suited for pistols and shotguns than rifles. 100 yards max.