Okla. Stat. tit. 31, § 31-13: Preservation trust - Revocable or irrevocable -

Contributions.

A preservation trust may be established as a revocable and

amendable trust or as an irrevocable trust. If the grantor of a

preservation trust revokes or partially revokes the preservation

trust, the exemption provisions of Section 12 of this title shall

not be applicable to any property received by the grantor as a

result of such revocation or partial revocation. The fair market

value of any property received by the grantor as a result of a

partial revocation shall increase the amount of property which the

grantor may contribute to the preservation trust pursuant to Section

12 of this title.