Mont. Code Ann. § 75-10-1402
Remediation schedule
75-10-1402 . Remediation schedule. Except as provided in 75-10-1411 , a person who undertakes a remedial action for the remediation of mine or smelter waste on property owned by someone other than the owner of the waste shall complete the remedial action in accordance with a schedule negotiated between the person completing the remedial action and the property owner and approved by the department.