Any bank, trust or insurance company organized under the laws of Oklahoma may invest its capital, surplus and reserves in bonds issued under the provisions of this article. The officers having charge of any sinking fund or any other fund of the state or any department, agency or institution thereof, including the various funds established by Article 17 of the Oklahoma School Code, or any county, city, town, or school district in the state, may invest such funds in bonds issued under the provisions of this article at the reasonable market value thereof. Such bonds are also approved as collateral security for the deposit of any public funds and for the investment of trust funds.
Okla. Stat. tit. 70, § 4009