Okla. Stat. tit. 30, § 30-3-220
Validation of prior conservatorships
All conservatorships created prior to the effective date of the
Oklahoma Guardianship and Conservatorship Act, Section 1-101 et seq.
of this title, with the consent of the person for whose property a
conservator was appointed, are hereby validated. Each such
conservatorship shall be presumed to have been created by consent
unless otherwise established by documents filed in the
conservatorship action or by other evidence.