Mont. Const. art. II, § 26

Trial by jury. The right of trial by jury is secured to all and shall remain inviolate. But upon default of appearance or by consent of the parties expressed in such manner as the law may provide, all cases may be tried without a jury or before fewer than the number of jurors provided by law. In all civil actions, two-thirds of the jury may render a verdict, and a verdict so rendered shall have the same force and effect as if all had concurred therein. In all criminal actions, the verdict shall be unanimous.