Oklahoma constitution
Article IX: corporations
Section 15

A Corporation Commission is hereby created, to be composed of three persons, who shall be elected by the people at a general election for State officers, and their terms of office shall be six years: Provided, Corporation Commissioners first elected under this Constitution shall hold office as follows: One shall serve until the second Monday in January, nineteen hundred and nine; one until the second Monday in January, nineteen hundred and eleven; and one until the second Monday in January nineteen hundred and thirteen; their terms to be decided by lot immediately after they shall have qualified. In case of a vacancy in said office, the Governor of the State shall fill such vacancy by appointment until the next general election, when a successor shall be elected to fill out any unexpired term.