Montana Constitution, Article XI
Section 4. General powers. (1) A local government unit without self-government powers has the following general powers:
(a) An incorporated city or town has the powers of a municipal corporation and legislative, administrative, and other powers provided or implied by law.
(b) A county has legislative, administrative, and other powers provided or implied by law.
(c) Other local government units have powers provided by law.
(2) The powers of incorporated cities and towns and counties shall be liberally construed.