S.D. Codified Laws § 50-4-8
All grants or funds accepted for disbursement by the department under §§ 50-4-3 to 50-4-7, inclusive, shall be deposited in the state treasury, and, unless otherwise prescribed by the authority from which the grants or funds are received, kept in separate funds, designated according to the purposes for which the grants or funds were made available, and held by the state in trust for those purposes. All grants or funds are continuously appropriated for the purposes for which the grants or funds are made available, to be expended in accordance with those sections. The department may, whether acting for this state or as the agent of any airport sponsor, or if requested by any department or agency of the United States, disburse the grants or funds for their designated purposes.
SDCL 50-4-8