Here is a nice photo of a Western Pacific boxcar in Elmira NY July 4 1989, about the same era as my ATSF in Roswell in the 90s layout.
Here is a similar car in Longview Texas on June 3, 2006.
These cars delivered lumber and other commodities for the Western Pacific throughout the country. Many of these cars are still on the rails today serving a similar role for the Union Pacific. (The Union Pacific bought the Western Pacific in 1983.)