Mich. Comp. Laws § 129.71: Investment of public moneys received by county treasurer and board of county road commissioners.

Sec. 1.

The board of supervisors of any county, or the board of county auditors in those counties having a board of county auditors, is hereby authorized to invest public moneys received by the county treasurers of their respective counties, in interest bearing bonds, notes or other securities of the United States government; and the board of county road commissioners of any county is hereby authorized to so invest moneys deposited to the credit of the county road fund.