Between the two vehicle bridges is a railroad bridge owned and operated by the Union Pacific Railroad. The railroad bridge was the first bridge at this location, built between April 1929 and October 1930 by the Southern Pacific Railroad. It is used by Union Pacific and BNSF (trackage rights) freight trains, as well as 36 scheduled Amtrak passenger trains each weekday. Passenger trains include the long-distance trains California Zephyr and Coast Starlight as well as Capitol Corridor inter-city commuter trains.