(Left) SDP40F 543 is fresh from it's stop at Stockton and has just crossed Western Pacific's mainline at grade. It's June 12, 1976 and the brief SDP40F era is nearing its end.

(Above) Thirteen months later, on July 16, 1977, F40PH 222 and three Amfleet cars mark the San Joaquin's transition from steam heat to head end power (HEP),  Amtrak's new standard for it's passenger car fleet.