Valley Railway (WWV) Walla Walla Valley Traction Company Washington–Oregon Corporation Washington Water Power Company Whatcom County Railway and Light Company Willapa Electric Company Willapa Harbor Railway Yakima Valley Transportation Company (YVT) Notes References Washington State Department of Transportation (September 2008), Washington State Rail System Map (PDF). Retrieved May 3, 2008. Washington State Department of Transportation (2004), Railroads in Washington State. Retrieved May 6, 2005. Watco Companies, Railroads. Retrieved August 15, 2005. External links provides finding aid to article subject from the Special Collections, Washington State Historical Society (WSHS) Washington Railroads