If you look in the middle of the center arch, you can vaguely make out the right-of-way etched out of the hillside where the pre-Oroville Dam mainline used to be. That, and other factors, leads me to believe the train is eastbound.

And I agree, it's a great photo.

A friend of mine who used to work in WP's headquarters in San Francisco told me once that WP, since they knew the state would be picking up the tab on the line relocation, requested, and received, the best of everything in state-of-the-art railroad construction techniques for 1962. High, top-grade ballast, continuous welded rail, and heavier rail than their mainline had on the original alignment. In other words, the quality of the track on the line-relocation was better than the rest of the railroad between Oroville and Keddie.