Ohio Rev. Code Ann. § 315.32

The plat and certificate made by any county engineer, or the depositions taken by such engineer, as provided by sections 315.28 to 315.31, inclusive, of the Revised Code, or a certified copy of such plat, certificate, or depositions from the engineer's office shall be evidence in any court in any cause in which the title of any land to which they apply is affected, but the depositions of witnesses so recorded shall only be received when such witnesses are dead or outside the jurisdiction of the court.