Okla. Stat. tit. 82, § 82-1131: Lawful securities for investments

Bonds issued under the provisions of this act are hereby made

securities in which all banks, trust companies, trust and loan

associations, investment companies, and others carrying on a banking

business; all insurance companies and insurance agencies and others

carrying on an insurance business, may lawfully invest funds,

including capital funds, under their control or belonging to them,

providing such bonds shall not be used by any depository as security

for any county or state funds.