S.D. Codified Laws § 47-18-5.1
A cooperative that owns shares of a domestic or foreign subsidiary corporation that carries at least ninety percent of the voting power of each class and series of the outstanding shares of the subsidiary that has voting power may merge the subsidiary into itself or into another such subsidiary without the approval of the board of directors or shareholders of the subsidiary, unless the articles of incorporation of any such corporation otherwise provide, and unless, in the case of a foreign subsidiary, approval by the subsidiary's board of directors or shareholders is required by the laws under which the subsidiary is organized. If approval of a merger by the subsidiary's shareholders is not required, the cooperative shall, within ten days after the effective date of the merger, notify each of the subsidiary's other shareholders, if any, that the merger has become effective. After the effective date of the merger or consolidation, the entities that were parties to the plan become a single cooperative. The procedure used to accomplish the merger or consolidation shall be as otherwise set forth in this chapter for mergers or consolidations of cooperatives. The subsidiary corporation shall be deemed the non-surviving cooperative for purposes of applying this chapter, as the context may require.
SDCL 47-18-5.1