SP 9025 East passes under the big signal bridge north of its yard in Stockton, CA. On the other side of the train is WP's mainline and its big yard. From this point northward through downtown Stockton, SP had four tracks at this period of time. The train is approaching the Santa Fe's main line and tower that guards the crossing.
The EMD SD (special duty) series are a strong and reliable kind of locomotive which still serve America's rails today. They have proved themselves reliable by clocking in several million miles of freight service over several decades.