The history of the San Fernando Valley from its exploration by the 1769 Portola expedition to the annexation of much of it by the City of Los Angeles in 1915 is a story of booms and busts, as cattle ranching, sheep ranching, large-scale wheat farming, and fruit orchards flourished and faded. Throughout its history, settlement in the San Fernando Valley was shaped by availability of reliable water supplies and by proximity to the major transportation routes through the surrounding mountains.

Calabasas is a city in the southwestern region of the San Fernando Valley in Los Angeles County, California, United States. Situated between the foothills of the Santa Monica and Santa Susana mountains, 29.9 miles (48.1 km) northwest of downtown Los Angeles, Calabasas has a population of 22,491.