The Santa Susana Pass Historic Park consists of more than 680 acres of preserved open space located at the boundary of Ventura County and Los Angeles County just east of Simi Valley and west of Chatsworth. The park, located where the Simi Hills meet the Santa Susana Mountains, offers panoramic views and includes portions of the Old Santa Susana Stage Road which was a stagecoach route between Los Angeles and San Francisco from 1861 to 1876. The park contains numerous hiking trails.

The Santa Susana Tunnel, built in 1900-1904 and reconstructed in 1992, is located beneath the Santa Susana Pass. It runs between Chatsworth and Simi Valley and is 7,369 feet long. The tunnel is used by Amtrak, Metrolink, and the Union Pacific Railroad.

Old Santa Susana Stage Road

The Old Santa Susana Stage Road, also known as the Santa Susana Wagon Road, is listed on the National Register of Historic places and is also a Historic-Cultural Monument in Ventura County. The historic road was completed in 1861 and served as the main stage route between Simi Valley and the San Fernando Valley until about 1875.

Santa Susana Depot

The Santa Susana Depot is an historic train station, located in Simi Valley, that opened in 1903. Southern Pacific closed the station in 1970, and shortly thereafter, it was purchased by Ventura County for $1.06. The county designated the building an historic landmark in 1976. A non-profit was formed to restore the property and it was opened as a railroad museum in 2000. It is operated by the Rancho Simi Parks and Recreation Department.