S.D. Codified Laws § 58-7-34
Upon the request of a domestic insurer, the director shall direct the depository or custodian to return to the insurer the whole or any portion of the assets and securities of the insurer held on deposit if the director is satisfied that the assets and securities to be returned are subject to no liability and are no longer required to be held by any provision of law or purposes of the original deposit. If the insurer has reinsured all its outstanding risks in another insurer or insurers authorized to transact insurance in this state and the insurer, by written notice, notifies the director that the assets and securities have been assigned, transferred and set over to the reinsuring insurer or insurers, the director shall require the depository or custodian to deliver the assets and securities to the insurer or insurers assuming the risks. The notice shall be accompanied by a duly verified copy of the assignment, transfer, or conveyance. In the case of deposits of the reserves of domestic life insurers, the insurers shall submit proof satisfactory to the director that the reinsurer has deposited or will deposit, and will maintain on deposit in public custody through the insurance supervisory official of its state of domicile, assets and securities of like quality in an amount not less than the reserves of the policies and contracts so reinsured, in addition to any other deposit of such insurer required or permitted by law. Unless the reinsurer is required to have on deposit all of its reserves, the insurer shall submit proof satisfactory to the director that the deposit of the reserves will be maintained by the state of its domicile for the special benefit and protection of the holders of the life insurance policies and annuity contracts so reinsured.
SDCL 58-7-34