Railway companies of South Dakota

List of railway companies in the American state of South Dakota.

Class I railways

 * Amtrak (AMTK), passenger on freight lines
 * Burlington Northern & Gulf Railroad (BNG), freight
 * North Western Pacific Railroad (NWP), freight and passenger
 * Pere Marquette Railway (PM), freight
 * Union Pacific Railroad (UP), freight

Shortline and terminal railways

 * D&I Railroad (DAIR), freight

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