Okla. Stat. tit. 53 § 1.18
The Oklahoma Historical Society shall dispense funds for historical purposes only as defined by paragraph 6 of Section 6 of this act. The Oklahoma Historical Society may enter into contracts with other state agencies or nonprofit corporations holding a valid exemption from taxation issued pursuant to Section 501(a) of the Internal Revenue Code of 1986, as amended, and listed as an exempt organization in Section 501(c)(3) of the Internal Revenue Code of 1986, of the United States, as amended, or with individuals or associations pursuant to statutory requirements.
Funds shall not be applied, donated or used directly or indirectly for the use, benefit or support of any sect, church, denomination or system of religion, or for the use, benefit or support of any priest, preacher, minister, or other religious teacher or dignitary, or sectarian institution as such. The Oklahoma Historical Society shall provide opportunity to organizations to submit written applications to be received and acted upon by the Oklahoma Historical Society. At the conclusion of the contract, each state agency, nonprofit corporation, individual or association shall provide the Oklahoma Historical Society with proof of fulfillment of the contract in proper order and must be affirmed on the proper form, provided by the Oklahoma Historical Society, by the managing officers of the state agency, nonprofit group, association or individual making the contract.
Okla. Stat. tit. 53, § 1.18