S.D. Codified Laws § 6-8B-17
No bond issued in registered form, whether initially or upon registration of transfer or exchange, is valid or effective for any purpose unless a certificate of authentication is executed thereon by the registrar, by the manual signature of its authorized representative. Any registered bond may be executed by facsimile signatures, printed or otherwise reproduced thereon, of any officers or other persons who are authorized or required by law to execute the same, or to execute any certification or countersignature thereon, and who have manually signed and filed with the registrar an authorization for the use of facsimile signatures, whether or not they have ceased to hold office before the authentication or delivery of the bond. Every bearer bond shall be manually signed on its face by at least one officer of the public body, or by an authorized representative of a banking institution designated by the governing body as authenticating agent but other signatures on the bond and any coupon pertaining to it may be facsimiles of manual signatures filed with the clerk. The corporate seal, if any, of the public body may but need not be affixed to any bond, or a facsimile of the corporate seal may but need not be printed thereon.
SDCL 6-8B-17