The 108-acre site, set in the bayside foothills of the Santa Cruz Mountains, is just east of San Andreas Resevoir. Geologically, the knoll that comprises the park is one quarter of a north-facing end slope of a ridge that was quarried over a 40-year time period for its Franciscan Sandstone. The park is bounded on its eastern side by the Serra Fault, while the much larger San Andreas Fault lies ¼ mile to west.

Junipero Serra Park contains valuable remnants of the Foothill Plant Communities that existed in the Bay Area before the coming of the European explorers and settlers. These communities are well suited to the climate, soils and topography of the area.

Common trees to be found in the park are the Coast Live Oak, Arroyo Willow, California Bay Laurel, Madrone, California Buckeye and the introduced Eucalyptus, Monterey Cypress and Monterey Pine. Animals seen in abundance are scrub jays, towhees, banana slugs, raccoons, red-tailed hawks and turkey vultures.

An abundance of spring wildflowers are found throughout the park, both on the grassy hillsides and in the wooded areas. The flowers include Douglas Iris, Miners Lettuce, Hounds Tongue, California Buttercup, Soap Plant and Owl Clover. Poison Oak grows abundantly throughout the park, and is to be avoided as it gives most people a skin inflammation, which can be severe.

All of the plant and animal species are protected in the park, and their habitats may be off limits to park users. Please observe signs carefully, and stay on marked trails and out of areas designated as protected.

Prepare for a safe and enjoyable visit to Junipero Serra Park and other San Mateo County Parks by being aware of your natural environment.