Okla. Stat. tit. 36, § 36-1609: County, district, city, school district or Canadian

obligations.

An insurer may invest in bonds, notes, warrants and other

securities not in default of any county, district, incorporated

city, or school district in any state of the United States, or the

District of Columbia, or in any province of Canada, which are the

direct obligations of such county, district, city or school district

and for payment of the principal and interest of which the county,

district, city, or school district has lawful authority to levy

taxes or make assessments. Bonds, notes, warrants and other

securities classified as revenue, prerefunded or declining balances

are not considered acceptable investments for this purpose.