The Tri-Valley – San Joaquin Valley Regional Rail Authority was created by the California Legislature in 2017 with the passage of Assembly Bill 758, co-authored by Assemblywoman Catharine Baker, R-San Ramon and Assemblywoman Susan Eggman, D-Stockton. The authority’s primary purpose is to plan, develop and deliver cost-effective transit connectivity between the Bay Area Rapid Transit District's rapid transit system and the Altamont Corridor Express’ commuter rail service.