Pacific Electric acquired the Ontario and San Antonio Heights Railroad Company on April 13, 1912,[1] bringing their Euclid Avenue Line in Upland as well as their branch to Pomona into the interurban network.[2] Connections to main line steam trains were made at Ontario Southern Pacific Station.[3] The Ontario–Upland Line was officially interlined with service to Pomona via North Pomona until 1918, after which Pacific Electric no longer advertised the route as such.[3] The line operated with an irregular schedule between Ontario and Upland until service was abandoned after October 6, 1928.[3]