San Bruno Mountain State Park, State park in San Mateo County, California, United States.

San Bruno Mountain State Park is a protected area in San Mateo County with diverse landscapes including grasslands, shrublands, and forested sections. The terrain rises from lower elevations to about 1,300 feet, creating varied hiking routes across the mountain.

The area became the nation's first Habitat Conservation Plan in the 1980s to protect endangered species from expanding urban development. This effort set a model for how threatened landscapes could be preserved through coordinated planning.

The mountain lies within the traditional territory of the Ramaytush Ohlone, whose villages and gathering places were spread across the San Francisco Peninsula. The park's name comes from San Bruno, a Spanish mission-era name given to the mountain and later carried by the city of San Bruno below it.

The park lies in northern San Mateo County, bordering Brisbane, South San Francisco, Colma and Daly City, with trails to the summit that afford views of San Francisco and the Bay Area. The mountain is a 4-mile (6.4 km) ridge, so plan routes around the open ridge sections where sun exposure is strong. Bring sturdy shoes and water; shade is limited.

The mountain harbors six plant species found nowhere else on Earth, along with three endangered butterfly species that depend on these specific conditions. This concentration of rare species makes it a hotspot for conservation efforts and scientific study.