San Bruno Mountain is a prominent fault-block horst in northern San Mateo County, California, rising 1,319 feet at Radio Peak, which hosts essential broadcast towers and provides expansive views of the San Francisco Bay Area. Much of its 2,326 acres are protected within the San Bruno Mountain State Park and an Ecological Reserve, safeguarding its distinct geology and unique ecosystems. This vital habitat supports several rare and endangered species, including the Mission blue and San Bruno elfin butterflies, alongside unique plants like the San Bruno Mountain Manzanita. Encircled by cities like Daly City (founded by 1906 earthquake refugees) and South San Francisco, the mountain holds significant historical and cultural relevance, notably inspiring Malvina Reynolds' 1964 hit song "Little Boxes." Additionally, the area includes the 1941 Cow Palace and the Guadalupe Canyon Industrial Park, which houses a quarry operating since 1895, reflecting its ongoing economic importance.