http://www.nprha.org/
http://www.trainweb.org/fredatsf/np54.htm
http://www.rr-fallenflags.org/np/np.html
http://raybob.boche.net/
http://www.nprymuseum.org/
http://www.trainweb.org/westernrails/wa/tumwaterbranch.html
http://www.davidrumsey.com/maps890113-24434.html