Black Mountain Ranch is a suburban community in the northern part of San Diego, California. Black Mountain Ranch encompasses 5,100 acres and is located north of Rancho Peñasquitos and Torrey Highlands, south of the Santa Fe Valley, east of Fairbanks Ranch and Rancho Santa Fe, and west of 4S Ranch. The development of Black Mountain Ranch took over 17 years to complete and was led by Fred Maas, a local San Diego businessman with a background in politics and sustainable building practices.