Railway companies of Idaho

List of railway companies in the American state of Idaho.

Class I railways

 * Amtrak (AMTK), passenger on freight lines
 * Burlington Northern & Gulf Railroad (BNG), freight
 * North Western Pacific Railroad (NWP), freight and passenger
 * Union Pacific Railroad (UP), freight
 * Washington & British Columbia Railway (WBC)

Regional railways

 * Spokane International Railroad (SI), British Columbia, freight and passenger

Defunct railways
Years shown here refer to the period in which a given company operated in Idaho; they may have existed elsewhere before or after these years.