South dakota constitution
Article XVII: corporations
Section 23

If a family farm corporation or family farm syndicate that has qualified under all the requirements of a family farm corporation or a family farm syndicate ceases to meet the defined criteria, it has twenty years, if the ownership of the majority of the stock of such corporation, or the majority of the ownership interest of such syndicate, continues to be held by persons related to one another within the fourth degree of kinship or their spouses, and their land holdings are not increased, to either requalify as a family farm corporation or family farm syndicate or dissolve and return to personal ownership.