After bagging Black Mountain Richard and I drove over to Castle Rock State Park (http://www.parks.ca.gov/?page_id=538) to get the Santa Clara county high point. We checked out the driveway mentioned in the other trip reports but didn’t feel confident about parking there. We went back to the nearest Castle Rock parking area and ran the 6/10th of a mile to the gated driveway. One gate was open and signed the other was closed but unsigned. We quietly jogged up the dirt road and spotted a tree heavily flagged with orange surveyor tape.
The benchmark was located next to the tree. The highest ground appeared to be a few feet SW of the benchmark. We took a few pictures and headed back to the car. Total time including taking pictures was 15 minutes for the approximately 1.5 miles round trip run.