Greenville Y reminds me of a trestle near here....between Greenville and Quincy near Keddie. It crosses over the Spanish Creek.
here are a couple of pix and flix of the Keddie Wye Trestle.
http://www.youtube.com/watch?v=Qc8F9rmMwGY
http://www.youtube.com/watch?v=lRVgSEGfHKA

i think this is the train track featured in an episode of Lassie
the dog show http://episodes.lassieweb.org/lassodsy.htm

included on this page is a pic of one of the most photographed bridges
just a couple miles from me (as the crow flies) Pulga Bridges
where hiway 70 and the rr trax cross the feather river. Pulga is Spanish for flea.

http://www.californiazephyr.org/resource_library/photo_archive/albums/frc_railfans_view.php