Mich. Comp. Laws § 600.807

Sec. 807. A probate court district is created in each of the following described districts when a majority of the electors voting on the question in each affected county approves the probate court district. The districts shall consist as follows: (a) The first district consists of the counties of Houghton and Keweenaw. (b) The fifth district consists of the counties of Schoolcraft and Alger. (c) The sixth district consists of the counties of Mackinac and Luce. (d) The seventh district consists of the counties of Emmet and Charlevoix. (e) The seventeenth district consists of the counties of Clare and Gladwin. (f) The eighteenth district consists of the counties of Mecosta and Osceola.