Okla. Stat. tit. 19, § 19-215.20: Election of district attorney - Tenure

At the primaries and general elections held in 1966, and each

four (4) years thereafter, there shall be nominated and elected in

each and every district attorney's district in the State of

Oklahoma, a district attorney, who shall hold office for a term of

four (4) years, beginning on the first Monday of January following

his election, and until his successor is elected and qualified.