Mich. Comp. Laws § 168.556: Nominating petitions; final disposition, record.

Sec. 556.

All nominating petitions filed under the provisions of this act shall be preserved by the secretary of state, county, city, village or township clerk, as the case may be, until the first day of January following the primary election for which the same were filed. At the expiration of that period, the secretary of state, county, city, village or township clerk may destroy all nominating petitions, the return of which has not been requested. In the record of nominating petitions, the various officers keeping such record shall cause entries to be made, stating the final disposition of each candidate's petition.