Okla. Stat. tit. 19, § 19-450: Determination of existence of vacancy - Jurisdiction and

proceedings.

For the purpose of determining whether such a vacancy exists the

district court is hereby vested with exclusive jurisdiction and the

district attorney of the county shall file a petition with the

district court of the county where such vacancy is alleged to exist,

and summons shall issue and be served in the manner provided by law

for the service of summons in other cases, and said cause shall be

tried to the court without the intervention of a jury and upon trial

thereof, if it be shown by preponderance of the evidence that the

county commissioner who is alleged to be incapacitated or

disqualified is suffering from any mental or physical ailment that

will prevent him from performing the duties of said office for the

balance of the term to which he was elected, the said court shall

enter judgment accordingly, decreeing that a vacancy exists, which

judgment shall thereupon be final and the vacancy shall be filled as

provided in Section 1 above.

Said action shall be brought by the district attorney and shall

be in the name of the State of Oklahoma on relation of the district

attorney as plaintiff, against the person who is alleged to be

disqualified and the summons shall be issued, directed to the

sheriff of the county where said defendant may be served, and if the

said defendant be in a hospital or under the care or supervision of

any institution, the same shall be served by delivering a copy

thereof to the said defendant and a copy to the person or officer

having supervision or control of the said hospital or institution

and said cause shall stand for trial at the first non-jury docket

setting after answer day, as other civil actions triable to the

court.