West Hills is a district in the western San Fernando Valley region of the City of Los Angeles in California, United States.
West Hills is bordered by the Chatsworth and Chatsworth Reservoir to the north, Canoga Park to the east, Woodland Hills to the south, Hidden Hills to the southwest, and the Simi Hills with the Upper Las Virgenes Canyon Open Space Preserve and Bell Canyon to the west. The community’s postal codes are 91307 and 91304.
Bell and Dayton Creeks in West Hills are several of the headwaters of the Los Angeles River that originate in the Northwest San Fernando Valley. The Los Angeles River itself begins at the confluence of Arroyo Studio City (Studio City Creek) and Bell Creek in Canoga Park. These and other small creeks supply stormwater and suburban runoff water to the Los Angeles River, and several are considered year round creeks. Although the creeks are now channeled and run within concrete walls, they do form a significant urban wildlife landscape and contribute to the population of indigenous wildlife left within the San Fernando Valley. Both Bell Creek and Dayton Creek in particular have received attention due to their original inside the Santa Susana Field Laboratory-SSFL. The SSFL is mandated for an environmental cleanup due to its uses as a testing center for rocket and missile fuel, nuclear power research, and high technology defense systems. It was also the site of a partial nuclear core meltdown in 1959. Prominent contaminants include VOCs, Chromium, Lead, Benzene, and other components of rocket engine fuel and cleaning.