There are not many free camp sites in San Jose or San Francisco, so I drove 9 hours to get here. My purpose was to setup and try my new tent out. Didn't camp overnight.
I think the most important thing to know is that the road is a single lane and there isnt a defined direction of travel. Be prepared to backup to the next turnout (if someone isn't. Already parked there.) Traffic will flow both ways. This can be dangerous in some spots. Fortunately traffic flow is very light.
You should also be careful of wild animals roaming the area. Cook downwind and several meters away from your camp. Also be sure you are not camping next to a fresh water source.
There were car campers and tent campers there when I went. I don't know if RVs are allowed, but they are not maneuverable here.
It is easier to find a camp w/ a hammock and cover setup. Tent camp sites tend to fill quick and people stay a while.
Bring drinking water and lip balm. For some reason I got extra thirsty and my lips started to dry. I regularly drink water and keep 10L in the car.
I saw a restroom at the entrance, but since it isn't close (and a risky night drive) I reccomend bringing a bottle(s) to pee in and a "Go Girl" for the ladies. Advice from an advid road tripper. It is best to go to the restrooms, even if your body doesn't tell you, right before nightfall.