Ohio Rev. Code § 307.32: Notice to board of county commissioners of county affected.

The board of county commissioners of a county where the county lines are to be run, shall give notice to the board of each county affected, declaring its intention of running the lines of such county. The board receiving the notice shall order the county engineer to run such lines with the engineers of the adjoining counties, at the time and in the manner fixed upon by the boards of such counties.