Mont. Code Ann. § 37-2-105

It shall be the duty of the county attorneys in the counties of the state, under the direction of the attorney general, to institute appropriate proceedings to prevent and restrain such violations. Such proceedings may be by way of complaint setting forth the case and praying that such violation shall be enjoined or otherwise prohibited. Upon the filing of a complaint under this section and the service thereof upon the defendants named therein, the court shall proceed as soon as possible to the hearing and determination of the action.