
Simi Valley remained a sparse ranching and farming community for much of its history before incorporating as a city on October 10, 1969. Just outside city limits, the Santa Susana Field Laboratory opened in 1948 as North American Aviation began developing and testing rocket engines there, and its Rocketdyne division went on to build engines used in the U.S. space program through the Cold War and Space Age. The city later became home to the Ronald Reagan Presidential Library, where the former president is buried.