A person may not cause or knowingly permit the person's child or ward under 18 years of age to drive a motor vehicle upon any highway when the minor is not authorized to drive or in violation of any of the provisions of parts 1 through 3 of this chapter.
Permitting Unauthorized Minor To Drive
Mont. Code Ann. § 61-5-304, under Miscellaneous Provisions.
Mont. Code Ann. § 61-5-304