S.D. Codified Laws § 40-31-13

Every dealer or producer charged by this chapter or by agreement with the keeping of records provided in this chapter shall, as the American Dairy Association by its regulations may require, file with the association a return on or before the fifteenth day of each month, on forms to be prescribed and furnished by the association stating the quantity of dairy products subject to assessment during the preceding month and such other information as the association may reasonably require. A copy of such return shall be retained by all dealers for inspection by the producers selling to them.