Contractor on site called me over once again because they hit something unknown.
Turned out to be a set of train tracks from original construction 1913-1915.
As can be seen here, there were a lot of tracks laid for construction. These veer off to the right to hook up with the ones below.
In this photo, lower right is about where the tracks are that the contractor dug up. I told them they would have to suspend their work until I talk with the historical people – these may be the tracks that President Woodrow Wilson’s train was on during his visit when the plant opened in 1915. Not. Montebello Lake is in the background.