S.D. Codified Laws § 51A-17-2.3
For purposes of § 51A-17-2, a letter of credit must be issued by a federally insured depository financial institution, a foreign bank that is authorized under federal law to maintain a federal agency or federal branch office in a state or states, or a foreign bank that is authorized under state law to maintain a branch in a state that bears an eligible rating or whose parent company bears an eligible rating and is regulated, supervised, and examined by United States federal or state authorities having regulatory authority over banks, credit unions, and trust companies.
The letter of credit must be irrevocable, unconditional, and indicate that it is not subject to any condition or qualifications outside of the letter of credit. It must contain no reference to any other agreements, documents, or entities or otherwise provide for any security interest in the licensee.
The letter of credit must contain an issue date and expiration date and expressly provide for automatic extension, without a written amendment, for an additional period of one year from the preset or each future expiration date, unless the issuer of the letter of credit notifies the director in writing by certified or registered mail or courier mail or other receipted means, at least sixty days prior to any expiration date, that the irrevocable letter of credit will not be extended.
SDCL 51A-17-2.3