Okla. Stat. tit. 19, § 19-297: Record of certificate showing Indian lands exempt from

taxation.

It is hereby made the duty of county clerks of Oklahoma to

record without charge all certificates describing and designating

lands situate in their respective counties owned by members of the

Five Civilized Tribes and their heirs, which lands are shown by said

certificates to be exempt from taxation under the provisions of

Section 4, of the Act of Congress, approved May 10, 1928, Public

Number 360 - 70th Congress; provided, said certificates when

presented for recording bear the approval of the Secretary of the

Interior.