Mont. Code § 87-5-112
This part may not be construed to apply retroactively or to prohibit importation into the state of wildlife that are lawfully imported into the United States or lawfully taken or removed from another state or to prohibit entry into the state or possession, transportation, exportation, processing, sale or offer for sale, or shipment of any wildlife whose species or subspecies is determined to be threatened with statewide extinction in this state but not in the state where originally taken, if the person engaging therein demonstrates by substantial evidence that the wildlife was lawfully taken or removed from the state. However, this section may not be construed to permit the possession, transportation, exportation, processing, sale or offer for sale, or shipment within this state of wildlife on the United States' list of endangered native fish and wildlife, as amended and accepted in accordance with 87-5-107(5), except as permitted in the provision by 87-5-107(3) and (4) and 87-5-109(1).
§ 87-5-112, MCA