S.D. Codified Laws § 51A-11-10
If the rental due on a safe deposit box has not been paid for one year, the lessor may send a notice by registered or certified mail to the last known address of the lessee stating that the safe deposit box will be opened and its contents stored at the expense of the lessee unless payment of the rental is made within thirty days. After such time the box may be opened in the presence of an officer of the lessor and a notary public. The notary public shall issue a certificate reciting the name of the lessee, the date of the opening of the box, the names of the witnesses present, and a list of its contents. The certificate with the contents of the box shall be included in a sealed package marked with the lessee's name and date of opening, and it shall then be placed in the general vaults of the lessor at a rental not exceeding the rental previously charged for the box until it is claimed or delivered to the state treasurer for disposal pursuant to chapter 43-41B. The state treasurer shall reimburse the lessor for unpaid box rentals from the proceeds of the package, if any.
SDCL 51A-11-10