Yes, its is between Mt. Montgomery and the tunnel. We're looking up toward the summit at this time. You will notice a fill showing at the left edge of the view, this is a photo of the fill:
The culverts are high enough for a man to walk through. There are some cuts that are equally deep!
And from the other side of the fill here is a view looking back at the retaining wall. This side of the summit had a ruling grade of 141 feet per mile or2.67%; on the north (or RR west) side it was 2.80%. It was a real mountain railroad! Special instructions called for brake test at the summit, using retainers, cycling the retainers, stops to cool wheels and inspect the train. Mt Montgomery at 7,140 feet was higher than Donner at 6,884 feet.
That's the Sierra Nevada in the distance.
Brian Norden