OK Const., Article XXIV, Section 2

Constitutional convention to propose amendments or new constitution. No convention shall be called by the Legislature to propose alterations, revisions, or amendments to this Constitution, or to propose a new Constitution, unless the law providing for such convention shall first be approved by the people on a referendum vote at a regular or special election, and any amendments, alterations, revisions, or new Constitution, proposed by such convention, shall be submitted to the electors of the State at a general or special election and be approved by a majority of the electors voting thereon, before the same shall become effective: Provided, That the question of such proposed convention shall be submitted to the people at least once in every twenty years.