Mont. Code Ann. § 15-24-905
Livestock brought into state -- notice to department
15-24-905 . Livestock brought into state -- notice to department. The owner or the agent, manager, or supervisor of any person, corporation, or association bringing livestock into this state after February 1 shall include the name of the owner of the livestock, the number of livestock, and the county or counties into which the livestock are moved on a livestock reporting form due on March 1 of the following year.