Okla. Stat. tit. 18, § 381.21

The corporate existence of an association shall begin on the date of filing of the certificate of incorporation with the Secretary of State and within thirty (30) days thereafter an organizational meeting shall be held by the deposit account holders or permanent capital stock subscribers pursuant to notice mailed to each of them not less than seven (7) days before the date of the meeting. At such meeting, bylaws of the association shall be adopted and directors shall be elected.