S.D. Codified Laws § 37-2-1
Any person, firm, company, association, or corporation, foreign or domestic, engaged in the business of selling gasoline, kerosene or liquefied petroleum gases within the state that shall intentionally, for the purpose of creating a monopoly, or of destroying the business of a regularly established competitor in any locality, discriminate by direct or indirect methods between different sections, communities, or municipalities of this state, by selling the above commodities at a lower rate in one section, community, or municipality, or any portion thereof, than such person, firm, company, association, or corporation shall charge for same in another section, community, or municipality, after making due allowance, if any, in the grade or quality, and the cost of transportation from the refinery, shall be deemed guilty of unfair discrimination, which is hereby prohibited and declared unlawful. A violation of this section is a Class 1 misdemeanor.
SDCL 37-2-1