SDCL § 15-2-28: Mortgage presumed paid after fifteen years--Tolling provisions not applicable.

At the expiration of fifteen years from the date the cause of action accrues on any mortgage as provided in § 15-2-5, such mortgage shall be conclusively presumed to have been paid and the mortgage and the record thereof shall cease to be notice of the mortgage as unpaid and the lien thereof shall then cease absolutely, and said period of fifteen years shall not be extended by nonresidence, legal disability, or partial payment.