I agree with Dan this is Boulder Gorge. The original bridge was a Howe truss style perported to be painted red, thus the location "Red Bridge". A number of old photos show the original bridge with a turn of the cent. train posing for the camera. The abbutment and grade are visible in the area ahead of the locomotive. The old highway was on a ledge above the rr which you can see a bit of driving up Hwy 7 just below were the photo was taken. After the rr was gone the Hwy was placed on the grade and enough rock blasted out that the ledge where the road was no longer exists in the area where the photo is.