New Mexico Magazine carried the story in spring 1976. The author claimed his father was engineer of 169, and that it and 170 were knocked off the track by a snow slide in 1906. 169 went on it's side, and 170 went down the hill. The wreck actually occurred right at milepost 315, about a quarter mile east of the tunnel.
They had to cut a grade to the east about 100 yards to bring the engine back up to the track. You can still see the flat spot and grade that were cut to get 170 out. The tender is still there, along with a bunch of spare parts left from the wreck. Must have been pretty violent, as the tender frame, cistern, and air tank are all separated. Trucks must have been worth retrieving, as they are not there.
I've attached a photo I took in '04. The frame is just below the center of the photo. The air tank is just beyond the cistern, out of view. Photo is looking down hill. The cistern is upside down, and if you look closely, you can just make out the numbers on its side.