Okla. Stat. tit. 16 § 20
A power of attorney in fact for the conveyance of real estate or any interest therein, or for the execution or release of any mortgage therefor, shall be executed, acknowledged and recorded in the manner required by this chapter for the execution, acknowledgment and recording of deeds and mortgages, and shall be recorded in the county where the land is situated, and no deed, mortgage or release of a mortgage executed by an attorney in fact shall be received for record or recorded until the power under which the same is executed has been duly filed for record in the same office; and the recording of any deed, mortgage or release of mortgage shall be of no effect for any purpose until the power under which it is executed has been duly filed for record in the same office. Provided that any power of attorney promulgated by any agency of the Government of the United States shall be deemed sufficiently recorded for purposes of this section if the promulgation thereof shall have been published in the Federal Registry of the Government of the United States and any instrument executed pursuant to said power of attorney recites the specific reference to said publication.
Okla. Stat. tit. 16, § 20