Okla. Stat. tit. 74, § 74-5062.11: Tax exemption for bonds

The bonds authorized pursuant to the Oklahoma Development

Finance Authority Act and the income therefrom, whether or not the

interest on which is subject to federal income taxation, shall be

exempt from all taxation in this state except for inheritance,

estate or transfer taxes; all legal instruments and all security

agreements and financing agreements made pursuant to the provisions

of this act shall be exempt from Oklahoma stamp, mortgage and

transfer taxes.