Mont. Code Ann. § 7-11-104

One or more public agencies may contract with any one or more other public agencies to perform any administrative service, activity, or undertaking or to participate in the provision or maintenance of any public infrastructure facility, project, or service, including the issuance of bonds for the joint construction of a facility under 20-9-404, the hiring of a teacher or specialist under 20-4-201 or a superintendent under 20-4-401, or the hiring of or contracting with any other professional person licensed under Title 37, that any of the public agencies entering into the contract is authorized by law to perform. The contract must be authorized and approved by the governing body of each party to the contract. The contract must outline fully the purposes, powers, rights, obligations, and responsibilities of the contracting parties.