For the purposes of chapters 47-15 to 47-20, inclusive, the street address, or the statement concerning the address, of a cooperative existing on July 1, 1965, becoming subject to said chapters, as set forth in the articles for its business office, shall be considered its registered office and the secretary of the cooperative shall be considered its registered agent unless either is amended pursuant to § 47-20-17.
SDCL 47-15-20