Western Pacific 1970's-80's in Northern Nevada and California

[mtrails]

I have been trying to research Western Pacific Railroad information on the web to find railmaps, timetables, and freight handling information, in the Northern Nevada and California region (namely Reno, through California, and into Oregon (Portland) and have had no luck. This particular single mainline of tracks were taken over (or operated by) Southern Pacific, not Union Pacific. Can anyone direct me to a website, or is anyone here knowledgeable of this rail system?