Mich. Comp. Laws § 331.54
The articles of incorporation shall be executed in duplicate and delivered to the county clerk of the county in which the local authority is located, who shall file 1 duplicate in his office and the other with the recording officer of the hospital authority when selected. The county clerk shall publish a copy of the articles of incorporation once in a newspaper designated in the articles of incorporation and circulating within the county. He shall file 1 printed copy of the articles of incorporation with the secretary of state and 1 in his office, attached to each shall be his certificate setting forth that the same is a true and complete copy of the original articles of incorporation on file in his office and also the date and place of the publication thereof. The local authority shall be established at the time provided in the articles of incorporation. The validity of the incorporation shall be conclusively presumed unless questioned in a court of competent jurisdiction within 60 days after the filing of the certified copies with the secretary of state and the county clerk.
MCL 331.54