Mich. Comp. Laws § 41.287: Validation of prior actions, special assessments, and bonds.

Sec. 17.

Actions heretofore taken, special assessments heretofore levied and bonds heretofore issued under this act, as originally adopted or subsequently amended, are validated. A board of county road commissioners acting under this act, or a township, shall not contest the validity of any such bonds after they are sold and delivered and the board of county road commissioners has received the consideration therefor.