Okla. Stat. tit. 58, § 58-53: Proof required

If, on the hearing, it appears upon the face of the record that

the will has been proved, allowed and admitted to probate in any of

the territories, or any state of the United States, the District of

Columbia, or in any foreign country or state, and that it was

executed according to the law of the place in which the same was

made, or in which the testator was at the time domiciled, or in

conformity with the laws of this state, it must be admitted to

probate, be certified in like manner according to the facts, and

recorded, and have the same force and effect as a will first

admitted to probate in this state, and letters testamentary or of

administration issued thereon.