This spur, approximately 2 miles long, extended from the still-active Union Pacific (ex-Pacific Electric, ex-Southern Pacific) El Segundo branch at a point called "Wise Transfer", just west of the BNSF crossing in El Segundo. The spur, originally built by Pacific Electric (PE) in 1914, headed northwest about 1.25 miles, then turned southwest for about another 0.75 miles to the corner of Grand Avenue and Concord Street. PE passenger service ended in 1930, and the line was likely cut back four blocks to the corner of Grand Avenue and Eucalyptus Drive at that time.
PE was a subsidiary of Southern Pacific and freight operations were merged into SP in 1965.
It is not known when the last freight train ran on this spur, but in December 1975 there was a "line closing ceremony" at the end of the line in El Segundo, and the last train (SP SW1500 2550 and passenger car SP110) ran on the line. The train was not open to the public. The rails were removed in 1976, and most of the ROW has been taken over by the neighboring business owners. In some places it is possible to see where the line cut through the city (there were many road crossings) but you cannot walk down most of the ROW because it is private property.
Thanks to Mike Palmer for contributing information about this route.