Okla. Stat. tit. 19, § 19-866.19: Termination of nonconforming uses

The board, within its area of jurisdiction may provide for the

termination of nonconforming uses either by specifying the period or

periods within which they shall be required to cease, or by

providing a formula or formulas whereby the compulsory termination

of nonconforming use shall be so fixed as to allow a reasonable

period for the recovery of amortization of the investment in the

nonconformance, provided, that in each instance any such action of

the board shall be taken only after public notice and hearing

thereon has been had before the commission and that commission's

recommendations with respect thereto certified to the board.