After which I found out I don't have all the Bay Area highpoints...
The day after hiking to the very top of the "San Francisco Bay Area Stadium", I hiked to the very top of Alameda County. Specifically, what's called "Challenger Peak". While nearby "Discovery Peak" had been considered the highpoint, it was recently dethroned due to LIDAR data. In fact, years before that happened, I had tried to do Discovery Peak but gave up (If you must know, I only got to the trailhead as it was getting dark then I saw a sign warning about mountain lions and got spooked.)
Anywho, this time I started in the morning-ish hours and I made a beeline for Challenger. Almost the entire trip was on wide fireroads with the exception of the spur to the peak. The stats were about 18 miles RT and 4500' of gain, with maybe a third of that on the return. I followed the right half of the route here but I dispute his stats based on what my heart rate monitor and two mapping sites say the stats are. He probably traveled a mile or two more and probably had more gain.
In any case, it was a lonely trip: I only saw two parties on the trail, and no one after the first couple of miles. There were plenty of people in the parking lot; despite the presence of blue-green algae, the lake and camping appears to be what most people come for. As for four-leggers, the area was teeming with life. I saw several deer, a couple of hares (on the return, near Boyd Camp), squirrels, and birds. I get the feeling that - at least during the summer - the trails are only infrequently used. I didn't see any signs of activity that looked definitively recent. There's a metal heavy equipment bridge across a gully to avoid a sharp turn in the road, but based on photos that's been there for over a decade. There were heavy equipment ruts in the road but who knows how long those have been there. I saw several cow patties but no cows.
The fact that the temps were pushing 90F might have contributed to how empty it was. There were occasional spots of dappled sunlight but it's mostly an open route. It didn't help that I'd gotten sunburned watching the game the day before. It also didn't help that some parts of the route are over private property and I had to go through, under, or over several gates.
I had earlier called asking for water info and they were only focused on the water fountains near the trailhead; it doesn't appear to be a backcountry park. While I pre- and post-hydrated as usual and carried 3L, I could have used more due to the temps. There's a working water faucet two miles in but it needs to be filtered. There was some water further up the trail but I wouldn't drink it except in an extreme emergency even if I'd filtered it a couple times. While backpacking filters can remove blue green algae cells, they don't remove the toxins those cells leave behind.
Not even worrying about the water, I kept on chugging up the fireroads until I got to the spur to the peak. While there's a little bit of a game trail and even a section where deer sleep, that spur was mostly through tall grass and I was on the lookout for snakes. I also checked for ticks afterwards.
Up top is a nice summit block of maybe 10' high. While if you're lucky it might be Class 2, I treated it like Class 3 because I was nine miles from the parking lot. It wasn't that difficult, I was just careful. I didn't see a register or a benchmark, but I didn't spend too much time looking. OTOH, if you look closely, you'll see I asked the summit block, "who's next?"
If you want to recreate my grand adventure, bear in mind that you'll be walking at least an hour or two through private property. There are several gates along the way and one of these days I'll create a version of this page that functions.
The "RK3" gate wasn't locked, just pull the handle (and then put it back). The next one is a rickety fence, just undo/redo the loop near my poles. The "RK1" gate had not just one but three locks. You could hop over it but I chose to take off my pack, get on my back, and shimmy under it. The next gate can be hopped near where my poles are. Then, there were a couple open gates. Bear in my I shot the photos of the gates on the return, so the time stamps are reversed.
I enjoyed the trip, and not just for the minor frisson of trespassing. However, only when I got back to L.A. did I find out I might not have all of the Bay Area county highpoints. Many years ago - I think January 2002 - I hiked Mt Diablo (Contra Costa highpoint) and then drove over to Mt Tam (Marin highpoint). At least I think it was then: I know I hiked Diablo when there was about a foot of snow on the peak, and that might have been the trip where I then did Mt Tam. OK, not that you care but anyway I think I only did the Mt Tam East, while West is the actual highpoint. So, I need to go back to be certain. I also visited Copernicus Peak at night and, since that was before the time of cell phones and modern conveniences, I should go back there during the day just to be sure. Yes, of course, these things are beyond trivial to sane people, but...