Montana Title 46. Criminal Procedure § 46-6-216. Manner of arrest with warrant

(1) When making an arrest pursuant to a warrant, a peace officer shall inform the person to be arrested of the officer's authority, the intention to arrest that person, the cause of the arrest, and the fact that a warrant has been issued for that person's arrest, except:

(2) The peace officer need not have possession of the warrant at the time of the arrest, but after the arrest, the warrant must be shown to the person arrested as soon as practicable if the person requests.