The Metrolink network consists of seven lines that run Bombardier bi-level coaches as well as Hyundai Rotem bi-level cars, hauled by locomotives. The network covers Ventura County, Los Angeles County, San Bernardino County, Orange Country, Riverside County and San Diego Country.
source= https://railway-news.com/amtrak-to-run-commuter-rail-services-in-southern-california/