Contra Costa County, CA

Mount Diablo State Park is known for its breathtaking views and diverse ecosystems, but it's also home to some intriguing and unusual features that make it a fascinating destination.

Contra Costa County, CA

Located on the popular Burma Road fire trail within Mount Diablo State Park, which offers access to the mountain’s summit, this man-made pond is stationed there for thirsty cows and other native wildlife. The goldfish, which have grown considerably over their years of residence on the mountain, offer a sustainable solution to keeping the water clean and free of pests. These goldfish eat algae that grows in the stagnant water, ensuring it remains clean and clear. They also eat mosquito larvae, effectively reducing the mosquito population and offering relief to both wildlife and human visitors alike.

Contra Costa County, CA

Mount Diablo State Park spans over 20,000 acres of open space, but visitors are still surprised to find a park-within-a-park when they arrive at Rock City. Located just a few miles past the South Gate entrance, Rock City features picnic areas, massive rock formations and stunning views, but most importantly: unique, maze-like wind caves. Although it may seem that these caves were man-made, they actually developed their unusual shapes over millions of years of erosion. Nonetheless, the caves are smooth to the touch and completely crawlable, serving as a natural playground for visitors.

Contra Costa County, CA

Different fossils can be viewed by visitors at numerous areas within Mount Diablo State Park, like Sycamore Creek and Rock City. However, the easiest fossils to access can be found at the mountain’s Visitor Center. When the Visitor Center was constructed in the 1930’s, they used stones quarried from different parts of the mountain. When walking along the outside of the Visitors Center towards the Observation Deck, look at the walls closely to find fossils of shells, embedded into the rock tens of millions of years ago.

Contra Costa County, CA

The East Bay Area is ripe with these furry, eight-legged creatures that primarily live underground throughout the year; that is, until mating season. Every year between late August and October, countless young, male tarantulas make their way above ground in search of female partners. These gentle giants can often be seen wandering across roads, trails, and open spaces, especially during warm, sunny days. When visiting Mount Diablo State Park in hopes of spotting these agile arachnids, make sure to keep a safe distance. They may appear intimidating due to their size and appearance, but they are generally docile and non-aggressive. Avoid touching or disturbing them. If you’re interested in photography, bring a camera with a telephoto lens to capture close-up shots without getting too close to the spiders.

Contra Costa County, CA

Visitors might be surprised to find that Mount Diablo State Park is home to over 150 wildflower species. In fact, Mount Diablo is one of the best places to go see wildflowers in the Tri-Valley, wearing patches of California poppies and purple lupines on its mountainsides every spring. However, there are a few wildflower species that primarily grow or originated in the park. Two of the most popular species exclusive to this region are the Mount Diablo Buckwheat and the Diablo Sunflower. The Mount Diablo Buckwheat is made up of small, delicate pink flowers and was feared to be extinct for several years, but was rediscovered in 2022 thriving in large numbers. The Diablo Sunflower is a member of the daisy and sunflower family and is a smaller, stouter version of what we consider regular sunflowers.