Okla. Stat. tit. 19, § 19-63: Parties to action - Duties of district attorney

Any suit commenced under the provisions of this article, shall

be brought in the name of the board of county commissioners of any

county interested in the subject matter of the suit, as plaintiff,

and any or all counties having any interest adverse to the plaintiff

may be joined as defendant. The district attorney of such county,

at the direction of the board of county commissioners, shall

commence and prosecute, or defend, as the case may be, to final

judgment and determination, any and all suits that may be instituted

under authority of this article.