SDCL § 43-28-18: Recording of instrument containing power affecting real property--Instrument of revocation must be recorded in the same office.

No instrument containing a power to convey or execute instruments affecting real property, which has been recorded, is revoked by any act of the party by whom it was executed unless the instrument containing such revocation is also acknowledged or proved, certified, and recorded in the same office in which the instrument containing the power was recorded.