San Ysidro Mountain

There are two primary routes to the summit of San Ysidro, the long multi-peak bagging route from Montezuma Valley road or via the route from Landmark Road. Earlier in the week, Susie Kara (the first 100 Peaks finisher!) pinged me and asked if I was hiking this weekend and if I wanted a hiking buddy. To which I quickly said yes to both. My plan was to summit San Ysidro and The Thimble.

Having already summited Bonny and White Benchmarks (along with Clyde and Hut), and given the traverse from White to The Thimble is a slog, Susie Kara and I opted to start from the Landmark Road trailhead.

We headed out from San Diego early, so as not to be caught in the hordes heading out to the desert to view the wildflowers. A storm had passed through the county on Thursday, so we knew it was going to be chilly. As we drove out, we could spot patches of snow on the mountains. However, both San Ysidro and The Thimble looked fairly free of the white stuff.

We parked to the left of the BLM sign, this area has a fair amount of private property, so navigating it can be tricky. That section between White Benchmark and The Thimble is a great example. Our route was not going to have this issue. The Subaru handled the dirt road again with no issues. As we left the car, the thermometer read 37°F, but the sun was shining and we were properly dressed.

The initial portion of the route follows an old jeep trail, so we made good time as we worked our way north, then to the east. The road kept climbing upward. Although one might be tempted to keep driving, a massive oak tree has fallen and blocked the road about 1/4 mile up. Thin patches of snow were scattered about.

At the junction, we made our right-hand turn to continue on toward the gully that we would use to reach San Ysidro. In reviewing other trip reports and routes, we knew the trail leaves the road just past a noticeable rock outcropping. We were also able to spot a few cairns along the hillside to validate our research. So, our cross-country portion began. There was a faint trail that guided us ever upward, but the terrain is fairly straight-forward to follow.

Eventually, we intersected the main gully that would lead us most of the way to San Ysidro. The Thimble stood above us to the East. Our plan was to tackle it on our way back.

The gully began to veer to the left, and the direct route stayed to the right. We opted for the direct route. As we began to gain elevation in earnest, we soon found ourselves surrounded by ice-covered plants and rocks. The ice had actually frozen horizontally! The ground was thankfully free from it. However, as we approached the summit, clouds blew in! What was clear 10 minutes before was now a grey mess. The winds also had picked up. They had been blowing a bit, but at the summit, it was very windy.

Susie was able to scramble the ice-covered summit block and sign the register and photograph the benchmark. The other marks were inaccessible due to the conditions. We quickly left the summit and dropped back below the clouds and discussed the rest of the day.

We could see The Thimble below us. Clouds drifted in and out, hiding its rocky face. We looked at various route options and discussed the conditions and risks. We are both experienced hikers, but we took careful stock of options. What if the conditions turn into a whiteout, can we navigate out? Will we be able to scale the rocks at the base of The Thimble? What about the actual route to the top?

In the end, we decided to work our way toward it, and honestly look at it and decided then if we would actually try to reach the top. We headed back down toward the gully, all the while looking at the conditions in the sky and on the peak. We cut across toward the northwest side. Eventually, our route was blocked by car-plus-size boulders that were too icy to deal with. We looped around to the east side to see what we might find.

I had no problem saying “not today”, as did Susie. We poked around the base of The Thimble, as we did not have the full route information for it (turns out we sort of did). But as we looked at it closer, we both decided that attempting the final push to the top would not be wise. The conditions on the top were going to be dangerous and not worth the risk. So, with that, we dropped back down to the gully. Along the way, a massive fly-by of Painted Ladies passed us. We stopped and just watched them flutter past.

As we worked our way back to the car, we noticed all the trash we had missed when we had started. Next time, I will pack a large trash bag to do some cleanup.

For me, both peaks are now crossed off my list, although I might be able to attempt The Thimble again soon with another 100 Peak Challenger who loves that summit.

I am an avid peak bagger, sometimes backpacker, and former sea kayaker living in San Diego. In 2019, I became the third person to complete the San Diego 100 Peak Challenge. Not stopping with that accomplishment, I set my sights on the harder San Diego Sierra Club 100 Peak list, which I completed in 2021. In addition, I have conquered several Six-Pack of Peaks challenges (SoCal, San Diego, Central Coast, and Arizona-Winter). Beyond attempting the San Diego Sierra Club 100 Peak list a second time, I am looking forward to exploring new summits and new adventures across the southwest. 

Leave a Reply

Your email address will not be published. Required fields are marked *