Okla. Stat. tit. 60, § 60-175.41: Revocation of trust by trustor

Every trust shall be revocable by the trustor, unless expressly

made irrevocable by the terms of the instrument creating the same.

Provided, that any trust may be revoked by the trustor upon the

written consent of all living persons having vested or contingent

interest therein. The term "contingent interest," as used in this

section, shall include an interest which a beneficiary may take by

purchase, and exclude any interest which a beneficiary may take by

descent. Provided further that this section shall not apply to a

spendthrift trust unless same is created by the trustor for his own

benefit.