Montana Constitution, Article XI
Section 7. Intergovernmental cooperation. (1) Unless prohibited by law or charter, a local government unit may
(a) cooperate in the exercise of any function, power, or responsibility with,
(b) share the services of any officer or facilities with,
(c) transfer or delegate any function, power, responsibility, or duty of any officer to one or more other local government units, school districts, the state, or the United States.
(2) The qualified electors of a local government unit may, by initiative or referendum, require it to do so.