Mont. Code Ann. § 70-25-204

70-25-204 . Wrongful withholding of security deposit -- action. (1) A person who wrongfully withholds a residential property security deposit or any portion of the deposit is liable in damages to the tenant in a civil action for an amount equal to the sum determined to have been wrongfully withheld or deducted. The attorney fees may be awarded the prevailing party at the discretion of the court. The burden of proof of damages caused by the tenant to the leasehold premises is on the landlord.