S.D. Codified Laws § 5-7-55
In addition to the annual rental, the lessee shall pay to the commissioner a royalty of not less than two percent of the gross returns from the sale of ores and mineral products derived therefrom, less reasonable transportation and smelting or reduction charges, if any, and such other customary and appropriate charges as determined by the commissioner by rules promulgated pursuant to chapter 1-26, of all ores or materials mined and extracted from the land. In addition, the lessee shall pay to the commissioner as royalty not less than two percent of any premiums and bonuses received in connection with the discovery, production or marketing.
Accounting for all royalties shall be made on the twentieth day of the month following the month of sale or receipt of premium or bonus.
SDCL 5-7-55