Okla. Stat. tit. 16, § 16-21: Revocation of power of attorney

No instrument containing a power of attorney for the conveyance,

mortgage, or lease of any estate or interest in real property which

has been recorded, is to be deemed revoked as to third parties by

any act of the person by whom it was executed, unless the instrument

containing such revocation is also recorded in the same office in

which the instrument containing the power of attorney was recorded.