Mich. Comp. Laws § 46.25: Construction, alteration or discontinuance of state or territorial roads; authority of board of supervisors.

Sec. 25.

That the board of supervisors of the several counties within this state, are hereby authorized and empowered to cause to be laid out, established, altered, discontinued or opened all state and territorial roads heretofore or now laid out, or hereafter to be laid through or within their respective counties whenever they may deem it for the interest of the public.