This short abandoned segment, just north of Barstow, CA, once formed part of the Atchison, Topeka and Santa Fe Railway's mainline to central/northern California. The line branched off the ATSF (now BNSF) transcon line near downtown Barstow at the eastern end of the large railroad yard there, bridged the Mojave River, then headed west to the town of Mojave, where it joined the Southern Pacific on a route through the Tehachapi Mountains.
When a larger yard was built at Barstow in the 1970s, west of downtown, the connection to the Mojave line was moved several miles to the west end of the yard. A remnant of the old mainline remained as a stub-end spur, listed as the "Waterman Spur" on a railroad atlas, but the bridge over the Mojave River was removed. Satellite imagery shows that the spur, and consequently the entire former mainline, has since been removed.
Thanks to Mike Palmer for contributing information about this route.