Tidbits: Highest point in Santa Clara County. ACCESS IS RESTRICTED.
When to go:
Anytime. Getting to the actual high point requires special access permission. See notes below.
Copernicus Peak is located ABOVE the Lick Observatory of the University of California on Mount Hamilton. You can access the summit area by heading 19 miles east on State Road 130 (Mount Hamilton Road) from Alum Rock Road off of Interstate 680 in San Jose. The road is a twisty, winding road with beautiful views of San Jose and the Santa Cruz mountains. Give yourself the better part of an hour to ascend the mountain by car. There are narrow lanes,. bicyclers, and lots of unprotected drop-offs. You can also approach from Livermore by taking Interstate 580 m to North Livermore Avenue south to Mines Road (which becomes San Antonio Valley Road). This route takes about 50 miles, although it is not quite so twisty.
The only legal place to park is at the Lick Observatory visitor's center at the apex of the road, or (which is closer) a small pullout just east of the visitor center parking area. The actual route to the high-point is about 100 yards east of the pullout. There are "NO PARKING" signs at a small paved secondary pullout area in front of a gate with additional "No Trespassing" signs. The actual summit is a 3-4 minute walk from this gate. You can walk around the gate and fence, but you will be trespassing and there are both University of California police officers and sheriff's officers that patrol the area every 10 or 15 minutes so it is not worth the risk.
Hotel and Climb Reservation:
While you can access the Lick Observatory, visitor center, and actually enter many of the telescope domes which are owned by the University of California, the actual high-point is in a restricted area and NOT accessible without special permission (see trip description below).
I had a free afternoon in the San Jose area and decided to try to tag the Santa Clara high point. Approaching from I680 (see directions above), the drive was absolutely stunning. Two notes...don't do it if you get car sick, and give yourself twice the amount of time you think you need to make the drive to the summit area. I made the 19 mile trip from the Interstate in just under an hour.
There are several large telescopes at the summit that are owned and maintained by the University of California, along with several small housing units for the astronomers. The public is welcome to visit the telescopes and enter many of the domes (I believe the hours are from 1:00pm to 5:00pm).
A fire tower sits on the actual high point, which is fenced off. Visitors are not permitted in this area. I saw a patrol officer from the University and spoke with him about the high point. He told me that sometimes, especially in the morning, if high-pointers approach him he will open the gate and escort them to the summit. I was at the summit area at 5:00pm and he was kind enough to open the gate and allow me 30 minutes to summit while he made his closing rounds. I was very appreciative of this kind gesture.
Basically there is a narrow path to the fire-tower. One of the "legs" of the tower is the actual high point. I should point out that the views from the actual high point are no better than the views in the summit area, so trespassing is not worth the risk. On my way back to San Jose I hit the last few miles at twilight and the view of San Jose lit up with the evening lights was very impressive.