Yes
Yes you can awsome trails
In Upper Ranch and Hudner Ranch, it seems you can: "Four-wheeled vehicles include jeeps, trucks, and side-by-sides/ROVs. ATV’s or motorcycles are not allowed in these areas, only in the lower ranch." source: http://ohv.parks.ca.gov/?page_id=1179
Yes in the 4wd side of the park and if it has a green sticker or licence plate.
I believe so, as long as its registered
Thanks! Your answer is awaiting moderation.