Montana Title 46. Criminal Procedure § 46-2-101. State criminal jurisdiction

(1) A person is subject to prosecution in this state for an offense that the person commits while either within or outside the state by the person's own conduct or that of another for which the person is legally accountable if:

(2) An offense is committed partly within this state if either the conduct that is an element of the offense or the result that is an element occurs within the state. In homicide, the “result” is either the physical contact that causes death or the death itself. If the body of a homicide victim is found within the state, the death is presumed to have occurred within the state.

(3) An offense that is based on an omission to perform a duty imposed by the law of this state is committed within the state regardless of the location of the offender at the time of the omission.

(4) This state includes the land and water and the air space above the land and water with respect to which the state has legislative jurisdiction.