She was constructed and operated by the Central Pacific Railroad to ferry entire trains (up to 48 cars at a time) on the Central Pacific transcontinental line to and from the San Francisco Bay Area. Once in service, the transcontinental railroad was re-routed to the sea level ferry crossing from its original course into the Bay Area via the Altamont Pass. Before her sister ship, Contra Costa, was constructed, Solano was the largest ferryboat ever built.