50 ILCS 10/1: Establishment.

The governing bodies of any two or more governmental units, including, but not limited to: counties, cities, villages, school districts, townships, and special purpose districts, and private regional organizations, may, by appropriate action enter into an agreement with each other, or with the governing bodies of any governmental unit of any other state to the extent that laws of such state permit, for establishment of a regional council of public officials.