SDCL § 49-16A-6: Freight charges to be uniformly applied--Unreasonable discrimination defined.

A railroad providing transportation may not charge or receive from a person a different compensation for a service rendered, or to be rendered, in transportation the railroad may perform than it charges or receives from another person for performing a like and contemporaneous service in the transportation of a like kind of freight under substantially similar circumstances. A railroad that charges or receives a different compensation for that service unreasonably discriminates.