Montana Title 39. Labor § 39-4-109. Cement plants and quarries

(1)(a) The period of employment may not exceed 8 hours a day for persons employed in or about cement plants and at quarries unless the employer and employee agree to a workday of more than 8 hours:

(b) Collective bargaining agreements covering cement plants and associated quarries that propose to extend the employment period beyond 8 hours a day must contain provisions that delineate the specific hours of work or other allowable situations agreed upon by the employer and the collective bargaining agent.