S.D. Codified Laws § 51A-4-20
No bank may employ its money, directly or indirectly, in the purchase of the stock of any other bank. However, a bank, or branch bank, may make reasonable contributions to local community agencies or groups to further the physical, economic, and social development of the bank's community. Such contribution may take the form of an investment in a corporation organized to carry on such activities and development. A bank may invest in a community development corporation and like entities and carry such investment as an asset on its books. However, the bank's investment in any one community development corporation or like entity may not exceed two percent of the bank's capital, surplus and undivided profits and the aggregate of all such investments held by the bank may not exceed five percent of the bank's capital, surplus, and undivided profits.
SDCL 51A-4-20