File:Western Pacific No. 913 at the California State Railroad Museum - April 2008.jpg

English: Western Pacific #913, an EMD F7 locomotive on display at the California State Railroad Museum in Sacramento, California.

One of the more well-known aspects of the Western Pacific was its operation of the California Zephyr passenger train, in conjunction with the Denver and Rio Grande Western Railroad and the Chicago, Burlington and Quincy Railroad. The WP handled the "Silver Lady" from Oakland, California, to Salt Lake City, Utah from 1949-1970. The Western Pacific owned several connecting short-line railroads. The largest and most well-known was the Sacramento Northern Railway, which at one time reached from San Francisco to Chico, California. Others included the Tidewater Southern Railway, the Central California Traction, the Indian Valley Railroad and the Deep Creek Railroad.

The Western Pacific was acquired in 1983 by Union Pacific Corporation, which would eventually purchase its long-time rival, the Southern Pacific Railroad, in 1996. In July 2005, Union Pacific unveiled a brand new EMD SD70ACe locomotive, Union Pacific 1983, painted as an homage to the Western Pacific as part of a new heritage program.