Oklahoma constitution
Article IX: corporations
Section 43

Every foreign corporation shall, before being licensed to do business in the State, designate an agent residing in the State; and service of summons or legal notice may be had on such designated agent and such other agents as now are or may hereafter be provided for by law. Suit may be maintained against a foreign corporation in the county where an agent of such corporation may be found, or in the county of the residence of plaintiff, or in the county where the cause of action may arise.