SDCL § 47-16-7: Member meetings--Quorum.

A quorum at a member meeting of a cooperative shall be ten percent of the first one hundred members plus five percent of additional members, present or represented by delegate. Unless the bylaws fix a larger number of members to constitute a quorum, a quorum may never be more than fifty members nor fewer than five members, or a majority of all members, whichever is smaller. Members represented by signed vote may be counted in computing a quorum only on those questions as to which the signed vote is taken. The sufficiency or requirement of a quorum for the transaction of business at a district meeting of members shall be established in the bylaws. However, the quorum may not be fewer than five members.