Mt. Hamilton stands tall at 4,265 feet (1,300 m) in the southern San Francisco Bay Area and part of the Diablo Mountain Range. The Lick Observatory at the top can be reached via a winding mountain road, popular with road cyclists to train and test their climbing abilities. When I lived in the South Bay, I took on that challenge multiple times, enjoying the views from the top.

However, one can take this to another level by turning the climb into a complete loop via the backside of the mountain, up north to Livermore and Pleasanton, and back south to San Jose. This had been on my bucket list for a while, and a weekend in mid-April felt like a good time to do it. In the summer, the interior area can reach temperatures up to 100F. Barring a death wish, one would reasonably attempt this in the spring or fall. In the past, a proper cycling event called “Mt. Hamilton Challenge” was held covering much the same route, but was discontinued after 2018.

I started out around 8am from Berryessa/North San Jose BART, making my way through local streets to Mt Hamilton Road and the 18.5 mile long but rather gentle climb to the top of the mountain (and as of this writing part of the Top 10 Most Scenic Bay Area Bike Climbs by PJAMM Cycling).

Leaving the outskirts of San Jose behind, the ride becomes increasingly remote as one gains elevation. Still, the views get more and more expansive. With lush green vegetation abounding in the spring, this is definitely one of the ride’s highlights. At the top, one can check out the observatory and enjoy vending machines and a water fountain to replenish nutrients and water.

The descent on the other side took me into San Antonio Valley, which felt yet another step up in remoteness. Upon researching the route, I initially hoped that The Junction (a roadside diner/pub place) would have re-opened since it apparently had changed owners frequently over the years. To be safe and not run the risk of running out of water, I brought along a 3-liter CamelBak reservoir with me, as well as plenty of bars and gels. The lack of options to resupply between the top of Mount Hamilton and Livermore makes this ride particularly challenging. (Note as of May 2024: The establishment is now called The Rainbow Junction Farm and the new owners are looking to re-open the restaurant in May/June 2024).

From The Junction, a roughly 30-mile trek along Mines Road awaited until I reached the outskirts of Livermore, which, together with Pleasanton, provides plenty of services, restaurants, coffee shops, and gas stations. The last section of the loop constituted the final endurance test of the ride: a climb to Calaveras Reservoir, past Sunol Regional Wilderness, a popular hiking spot on weekends. While not difficult, it tests one’s mettle with already 90 miles covered.

Eventually, I made it to the top of the climb, where I made the final descent into the eastern edges of Milpitas and covered the rest of the route back to the starting point.