Louisiana Revised Statutes Tit. 9, § 2262.4. Form

A trust instrument executed outside this state in the manner prescribed by, and in conformity with, the law of the place of its execution, or the law of the settlor's domicile, at the time of its execution shall be deemed to be legally executed and shall have the same force and effect in this state as if executed in the manner prescribed by the laws of this state, provided the trust instrument is in writing and subscribed by the settlor.