Okla. Stat. tit. 60, § 60-175.91
Validity of trust provisions
A. A provision which provides that a current distribution
interest shall either become a discretionary interest or shall
terminate upon the attachment by a creditor, including an exception
creditor, is valid.
B. A provision that provides a remainder interest shall
terminate or change into a dynasty interest upon attachment by a
creditor, including an exception creditor, is valid.