Santa Susana Pass State Historic Park preserves a rugged meeting place of the Simi Hills and Santa Susana Mountains on the Los Angeles-Ventura county line, valued for both scenery and deep cultural history. Its historic core includes traces of Fernandeño and Chumash trading routes and village sites, showing the pass's long role in movement and exchange. It later became a major Southern California transportation corridor, and surviving sections of the Old Santa Susana Stage Road recall the years from 1861 to 1876, when mail and travelers used this route northwest from Los Angeles. Despite later land changes and modern threats, the park remains open as an important historic and open-space link.