SF Zephyr arrive at Oakland: My 70's photos:https://www.railpictures.net/album/8659/
Amtrak's "Rainbow Era" was over by early 1975 as Amtrak #621 lead Train #6 over the Truckee River East of Verdi. The sixth car in the consist was one of SP's home-built dome cars.
Union Pacific #956 is now working for Amtrak and will later become Amtrak #429.
Ready head North to Cheyenne with #5, the Westbound San Francisco Zephyr is at Denver Union Station. At that time, #5 still operated over the UP from Cheyenne over to Ogden.
Westbound - just departed Denver Union Station.
