Black Mountain is a summit on Monte Bello Ridge in the Santa Cruz Mountains of west Santa Clara County, California, south of Los Altos and Los Altos Hills, and west of Cupertino. It is located on the border between Rancho San Antonio Open Space Preserve and Monte Bello Open Space Preserve, with the summit located in the former. Early Spanish explorers commonly named tree- or chaparral-covered summits which look black in the distance Loma Prieta, from the Spanish (loma-hill, prieta-dark). The Spanish also called the middle portion of the Santa Cruz Mountains the Sierra Morena meaning (morena-brunette, sierra-mountain range), extending from Half Moon Bay Road (California State Route 92) south to a gap at Lexington Reservoir, and which includes a summit called Sierra Morena.