Okla. Stat. tit. 68, § 68-1903: Exemptions prohibited

No mortgage of real property situated within this state shall be

exempt, and no person or corporation owning any debt or obligation

secured by mortgage of real property situated within this state

shall be exempt, from the tax imposed by this article by reason of

anything contained in any other statute, or by reason of

nonresidence within this state, or for any other cause.