(1) A person commits the offense of criminal trespass to vehicles when the person purposely or knowingly and without authority enters any vehicle or any part of a vehicle. (2) A person convicted of the offense of criminal trespass to vehicles shall be fined not to exceed $500 or be imprisoned in the county jail for any term not to exceed 6 months, or both.
Criminal Trespass To Vehicles
Mont. Code Ann. § 45-6-202, under Criminal Trespass and Burglary.
Mont. Code Ann. § 45-6-202