Mont. Code Ann. § 70-6-209

A depositary who believes that a thing deposited with the depositary is wrongfully detained from its true owner may give the owner notice of the deposit, and if within a reasonable time afterwards the owner does not claim it and sufficiently establish a right to the thing and indemnify the depositary against the claim of the depositor, the depositary is exonerated from liability to the person to whom the depositary gave the notice upon returning the thing to the depositor or assuming, in good faith, a new obligation changing the depositary's position in respect to the thing to the depositary's prejudice.