This abandoned railway was initially constructed as the San Pedro, Los Angeles & Salt Lake, and the line from Los Angeles was completed to Riverside (Riverside Junction) in 1905. The SPLA&SL, which later shortened its name to Los Angeles & Salt Lake, was affiliated with the UP from the start.
Between Riverside Junction and Daggett (north/east of Barstow), the UP line had trackage rights over the Southern Pacific (Riverside to San Bernardino) and Santa Fe (San Bernardino to Daggett) to get across Cajon Pass. Santa Fe later allowed through UP trains to use its rails for the entire route between Riverside Junction and Daggett. In the early 1980s, the UP extended its "shared track" arrangement with the AT&SF about a mile to West Riverside, where a new connection between UP and AT&SF was built. This short segment of UP in downtown Riverside, that included the station, was abandoned in the mid 1980s.
This station is easily seen from the adjacent Riverside Freeway (CA Route 91). Most of the local industrial sidings in downtown Riverside are gone, but some new tracks were installed for the nearby Metrolink commuter station in the 1990s.
See also The Rialto Branch.
Thanks to Mike Palmer for contributing information about this route.