North Dakota Constitution Art. VII, § 10

Agreements, including those for cooperative or joint administration of any powers or functions, may be made by any political subdivision with any other political subdivision, with the state, or with the United States, unless otherwise provided by law or home rule charter. A political subdivision may by mutual agreement transfer to the county in which it is located any of its powers or functions as provided by law or home rule charter, and may in like manner revoke the transfer.