Mont. Code § 67-11-102
Any municipality may, by resolution of its governing body, create a public body, corporate and politic, to be known as a municipal airport authority which shall be authorized to exercise its functions upon the appointment and qualification of the first commissioners thereof; or the governing body may by resolution determine to exercise any or all powers granted to such authorities in this chapter until or unless such powers are or have been conferred upon a municipal or regional airport authority. Upon the adoption of a resolution creating a municipal airport authority, the governing body of the municipality shall, pursuant to the resolution, appoint not less than five persons as commissioners of the authority. The commissioners who are first appointed shall be designated to serve for terms of 1, 2, 3, 4, and 5 years, respectively, but thereafter each commissioner shall be appointed for a term of 5 years, except that vacancies occurring otherwise than by expiration of the term shall be filled for the unexpired term by the governing body.
§ 67-11-102, MCA