SVRy trestles

I have been trying to determine accurate dimensions for bents in the Alder Springs trestle. In Ferrell's "Rails, Sagebrush and Pine," page 30, there are two pictures of trestles, but the bents in the smaller picture have two verticle center piles while those in the larger picture have three. Was the trestle rebuilt at some time between the two pictures, or are these at two different locations? I am convinced that the smaller picture with #250 pulling the lumber cars is on the Alder Springs trestle. Also later in the book, p. 65 is a picture of a trestle very similar to the one on p.30 that the caption indicates is at Johnson's Jumpoff just below Larch. I would appreciate a more detailed location for this trestle. Many thanks for any help.