Alum Rock Park: Outdoor Adventures in San Francisco Bay Area

Alum Rock Park in San Jose, California is one of our recent outdoor adventures we’d love to share with you. Can’t believe we’ve lived in the SF Bay Area for years, and this was our first visit! Don’t make our mistake. If you are near San Jose and looking for a beautiful hike in a historical setting, Alum Rock Park is a great place to start.

Alum Rock Park History and Curiosities

Founded in 1872, Alum Rock Park is the oldest municipal park in the entire state of California! Modeled after European spa retreats, the park boasted close to 30 mineral hot springs, baths, pavilions, Tea House, and even a hotel. Alum Rock Park was the place to see and be seen at the time. What a happening spot it was!

In the spring of 1911 major flooding caused severe damage to the park, wiping out the narrow-gauge railroad line, taking out small bridges, and destroying the park’s water system. A couple of years later a new railroad was built, and patrons could once again enjoy their round-trip ride from downtown San Jose for just $0.25 cents. Alas, with the increasing popularity of automobiles, the railroad ceased to exist.

Along the way to Alum Rock Park, the train would stop by the largest “meteor” on the planet. A massive 2,000 ton rock of manganese oxide, about 15 feet in diameter, was near the entrance to the park. Although, some geologists of the time did not agree that it was a “meteorite” at all. Geological mystery? Maybe. Look at the sheer size of that Rock! That’s a lot of manganese oxide! 😊

Some research indicated that the “meteor” was taken and melted down in 1917 to assist with the war efforts. However, by some other accounts, the City sold it to a “mining man” for $22,000 who later discovered that the rock weighted only 389 tons, and was only able to extract 39 pounds of manganese from it. So, the buyer went broke, the City was never able to collect the money owed, and Alum Rock Park lost one of its unique attractions. Which version is true, we might never know…

The Great Depression and then World War II later left the park in pretty bad shape. But Alum Rock Park experienced a huge revival post World War II. The Natatorium (indoor public pool, originally built in 1912-1916) was a popular place, together with the hot springs, a carousel, and occasional orchestra and band performances. Eventually, overuse brought the disbalance to the park’s ecosphere, and Alum Rock Park went downhill yet again by the 1960s.

In the 70s, a decision was made to remove most of the man-made structures and concentrate on the natural beauty of the area.

However, while hiking on the trails, you can still see the remaining grottoes, mineral springs, and stone bridges of the bygone eras.

There is even a log cabin donated to the City of San Jose in 1916 by Native Daughters of the Golden West that is still standing there. It was constructed using redwood logs from the Santa Cruz mountains. It serves as a memorial to the pioneers, representing how they lived and worked.

We found this photo of the actual dedication ceremony of 1916 at the Youth Science and Nature Center in Alum Rock Park. Isn’t it cool?

Youth Science Institute

Speaking of Youth Science and Nature Center, the YSI has been maintaining the Alum Rock Park since 1953. And the Center is a fun place to visit for kids AND adults. There is a natural history exhibit, and a room with teaching living animals as well.

In addition, YSI has an aviary for taking care of injured birds of prey who can no longer be released back into the wild.

The friendly staff of the YSI Center is always willing to answer your questions! Check this site for the upcoming events, including dusk walks with docents to see the wildlife. One of the biggest family events of the year is in October – Annual Wildlife Festival, complete with owl ambassadors, live animals and nature walks!

Alum Rock Park Environment

Alum Rock is also the largest park of San Jose, sitting on 720+ acres, with multiple well-maintained trails, about 13-miles of them available for hikers & bikers.

Penitencia Creek, South Woodlands and Inspiration Point Loop are the easiest trails. Eagle Rock Trail is for the best views of the Santa Clara Valley, from the San Francisco Bay to the Los Gatos Hills. Sycamore Switchbacks Trail is the steepest one and, thus, the most strenuous.

It is a popular place for weekend family picnics and outdoor celebrations. All the facilities are there, a ton of sitting areas (about 150 tables!), plenty of barbecue grills, and two large playgrounds, shaded by century-old trees.

And be aware of these little rascals, jumping around the picnic areas. The ground squirrels are everywhere in Alum Rock Park, and they are not shy to pose for some photos!

What’s in the Name?

Why Alum Rock Park? Originally, the area was known as “The Reservation”. The first time the name Alum Rock mentioned was in the 1890s. This came from the white coating on the rocks near the mineral springs, that was supposed to be composed of “alum”. It wasn’t. As a matter of fact, there is no alum in the Alum Rock Park at all. 😊 That white coating is a sodium sulfate mineral.

The creek, running through the park, was originally called Shistuk, a “place of rabbits”, by the Ohlone People, native to the San Francisco Bay Area. The Spaniards called it Aguague “Watering Place”, and Penitencia Creek later on by Friars, who used this creek or a similar one in the area, as a place for Penance.

All in all, our first experience in Alum Rock Park was relaxing and educational, a perfect place to spend an afternoon outdoors. Next time we are planning to bring friends with us for a BBQ picnic, and then hike to the top of the Eagle Rock trail for the splendid views of the Bay Area.

Tips from Locals

Parking close to the Visitor’s Center and Young Science and Nature Center is only $6.00 per car — and it’s definitely worth it. There are also two complimentary parking lots at the entrance of the park, but those are farther away from the main facilities and picnic areas. And, unfortunately, dogs are NOT allowed in Alum Rock park.

For additional information about Alum Rock Park, please check their website.

For all our cyclist friends and readers, please check this awesome detailed video tour by Ian Kluft!

And for more outdoor adventures in the San Francisco Bay Area, check out our posts on Rancho San Antonio, Ulistac Natural Area, and San Jose Rose Garden, to name a few. MonkeysVentures was named a local expert on Redfin. Check out the article we were featured in: 9 Awesome San Jose Suburbs to Consider Living In | Redfin

We love hearing from you, so comment away below. Have you been to Alum Rock Park in San Jose? We’d also like to hear what is in your backyard for outdoor adventures! And don’t forget to subscribe to our blog! 😊