Milagra Ridge was first inhabited by the Ohlone, later claimed by Spanish settlers and Mexican ranchers, and bought by the US Army in the late 1930s for the defense of San Francisco Bay. It held Battery 244 and, from 1956, the Nike missile site SF-51.
The National Park Service acquired the remaining 240 acres in 1987. Volunteers have worked to protect the Mission blue and San Bruno elfin butterflies, the San Francisco garter snake and the California red-legged frog. The Milagra Battery Trail opened in November 2016.