Strict liability stops at the city limits
MCA 27-1-715 makes the owner of a dog that bites, without provocation, a person in a public place or lawfully on private property located within an incorporated city or town liable regardless of the dog's former viciousness or the owner's knowledge. A person is lawfully on private property when performing a legal duty or as an invitee or licensee of the person in possession.
Outside cities and towns, a victim relies on scienter, negligence or negligence per se. Provocation and trespass are the defenses written into the statute, and the Montana Supreme Court has said provocation is a case-by-case question.