The Western Pacific Railroad was a Class I railroad in the United States. It was formed in 1903 as an attempt to break the near-monopoly the Southern Pacific Railroad had on rail service into northern California. WP's Feather River Route directly competed with SP's portion of the Overland Route for rail traffic between Salt Lake City/Ogden, Utah, and Oakland, California, for nearly 80 years. The Western Pacific was one of the original operators of the California Zephyr passenger line.

The Overland Route was a train route operated jointly by the Union Pacific Railroad and the Central Pacific Railroad/Southern Pacific Railroad, between the eastern termini of Council Bluffs, Iowa, and Omaha, Nebraska, and the San Francisco Bay Area, over the grade of the first transcontinental railroad which opened on May 10, 1869. Passenger trains that operated over the line included the Overland Flyer, later renamed the Overland Limited, which also included a connection to Chicago.