Okla. Stat. tit. 11, § 11-47-123: Saving vested rights

In any instance where it is shown that the application of the

terms of Sections 47-101 through 47-124 of this title, or any

proposed action hereunder, will be in material conflict with any

accrued vested right so that it would, if applied to the particular

property involved, result in substantial harm, loss, damage or

impairment, such right shall be preserved, recognized and given

effect and may be protected by any remedy herein provided for.