S.D. Codified Laws § 9-39-4.1
A municipal corporation, which operates its own electric distribution system, whether or not a member of a municipal power agency, may by resolution of its city council and utility board, if any, enter into a contract or contracts with one or more municipal power agencies for the purchase, sale, exchange, or transmission of electric energy extending for such term of years and with such provisions for the charges made thereunder as determined in the authorizing resolution or resolutions. Every resolution adopted in accordance with this section shall be published in the official newspaper of the first or second class municipality. No action may be brought and no defense may be interposed in an action brought more than twenty days after publication of the resolution, placing at issue the validity of any provision of the resolution or the power of the municipality to make any contract or incur any obligation authorized thereby. The provisions of §§ 9-39-36 to 9-39-39, inclusive, shall not apply to the resolutions or contracts.
SDCL 9-39-4.1