S.D. Codified Laws § 44-9-24
No lien may be enforced in any case unless the holder of the lien asserts the lien, either by complaint or answer, within six years after the date of the last item of the lien holder's claim as set forth in the filed and entered lien statement. No person is bound by the judgment in the action unless the person is made a party to the action within the six-year period.
If no action or suit has been commenced to enforce the lien during the six-year period, the owner of the property, the owner's agent, or contractor may file an affidavit with the register of deeds stating that the lien holder has not commenced suit to enforce the lien within the six-year period and requesting that the lien be cancelled. The register of deeds shall cancel the lien of record within thirty days of the filing of the affidavit.
SDCL 44-9-24