Correction: I wasn't paying enough attention. Red Bridge 2 is what I had referred to as the Heavy Duty trestle. Sorry about that, chief!
Actually, the location shown is in error. Boulder Gorge, and the site of the Red Bridge 1, Red Bridge 2 and the heavy duty trestle that replaced the 2nd red bridge was several miles east of Philips Lake, and is not under water. Highway 7 still passes through the site. When I first visited the bridge site in 1977, It was easy to compare the rocks alongside the highway to the railroad photos and see that it was the same site. When they turned the county road into Highway 7 they widened the road to add shoulders and widen the lanes a little, and in doing so the rocks were cut back, so it is not quite as recognizable as it used to be. I could only find one of the concrete blocks that once supported the third bridge in the river. Attached is a Google satellite view with the actual location of Bolder Gorge and the bridge site marked.
Both bridges were build in the same and by reading your comment and comparing the image to google street view imagery, I have found out that this is the actual location
of the two bridges not under Phillips Reservoir like I thought originally thought. Thank you for correcting the location.