The Santa Susana Field Laboratory (SSFL), formerly known as Rocketdyne, is a complex of industrial research and development facilities located on a 2,668-acre (1,080 ha) portion of Southern California in an unincorporated area of Ventura County in the Simi Hills between Simi Valley and Los Angeles. The site is located approximately 18 miles (29 km) northwest of Hollywood and approximately 30 miles (48 km) northwest of Downtown Los Angeles. Sage Ranch Park is adjacent on part of the northern boundary and the community of Bell Canyon is along the entire southern boundary.