Ohio Rev. Code § 315.31: Record of plat.

Any county engineer making surveys under sections 315.28 to 315.30, inclusive, of the Revised Code, shall record the plat and certificate of such surveys in a book kept by him for that purpose, together with the depositions, notices, advertisements, and the evidence in relation to such depositions, notices, and advertisements, and shall, on demand, deliver the original plat and certificate of the survey to the person at whose instance such survey was made or depositions taken.