Mont. Code Ann. § 67-11-232

Except as may be limited by the terms and conditions of any grant, loan, or agreement authorized by 67-11-305, an authority may, by sale, lease, or otherwise, dispose of any airport, air navigation facility, or other property or portion of or interest in an airport or facility acquired pursuant to this chapter. The disposal by sale, lease, or otherwise must be in accordance with the adopted rules of the authority, which rules must be approved by the local governing body, for the disposal of county property, except that in the case of disposal to another authority, a municipality, or an agency of the state or federal government for use and operation as a public airport, the sale, lease, or other disposal may be effected in a manner and upon terms as the commissioners of the authority consider to be in the best interest of civil aviation.