The Sacramento Northern's Rockville Branch served agricultural areas of Solano County. The branch was Y-shaped, and connected to the SN main over tracks that are now operated by the Western Railway Museum. The branch crossed over the Southern Pacific Oakland-to-Sacramento mainline on a bridge, and then divided into two legs. One branch headed north-northwest to Vacaville, while the other headed southwest to Fairfield (near Rockville). These routes were abandoned after packing houses switched to trucks or closed, and the associated farmland was sold to developers.