Montana Title 45. Crimes § 45-8-103. Riot

(1) A person commits the offense of riot if the person purposely and knowingly disturbs the peace by engaging in an act of violence or threat to commit an act of violence as part of an assemblage of five or more persons and the act or threat presents a clear and present danger of or results in damage to property or injury to persons.

(2) Except as provided in subsection (3), a person convicted of the offense of riot shall be fined not to exceed $500 or be imprisoned in the county jail for a term not to exceed 6 months, or both.

(3) A person who commits the offense of riot by engaging in an act of violence while incarcerated at any state adult correctional facility or city or county jail shall be imprisoned for not less than 1 year or more than 5 years.