Mont. Code Ann. § 70-1-701

It is the purpose of this part to declare that a gift or devise may be made to the estate of a named or otherwise designated person and that a power to appoint to the estate of such a person may be created and exercised in order to ensure that persons who make inter vivos or testamentary conveyances that are subject to the law of Montana can effectively use forms of conveyances that are commonly used in other states to qualify for the federal estate and gift tax marital deductions.