Cal Northern GP15 104 at Petaluma CA Apr 9 1994 Brian Solomon 661619 April 9, 2013 800 × 1226 California Northern, Petaluma, California April 9, 1994. A former Chicago & North Western GP15-1 at the old Northwestern Pacific station in Petaluma on April 9, 1994. Like this:Like Loading... California Northern at Petaluma. Share this:FacebookEmailTwitterMoreWhatsAppLike this:Like Loading...