S.D. Codified Laws § 51A-5-14
Any bank, when holding securities as custodian for a fiduciary may deposit, or arrange for the deposit, with the federal reserve bank in its district of any securities the principal and interest of which the United States or any department, agency, or instrumentality of the United States has agreed to pay, or has guaranteed payment, to be credited to one or more accounts on the books of the federal reserve bank in the name of the bank. Any account used for this purpose shall be designated as a fiduciary or safekeeping account, and other similar securities may be credited. A bank depositing securities with a federal reserve bank is subject to such rules and regulations with respect to the making and maintenance of such deposit, as, in the case of state chartered institutions, the commission, and, in the case of national banking associations, the comptroller of the currency, may from time to time issue.
SDCL 51A-5-14