Ohio Rev. Code § 5519.05
The director of transportation, when he acquires property for highway purposes, either by purchase or appropriation, shall promptly monument the right-of-way line of the property acquired.
The director, as soon as practicable in view of the availability of the funds and forces of his department, shall definitely and accurately ascertain and monument the roads and highways on the state highway system. At the discretion of the director, such monuments may be located in the center line of the highway or improvement.
The director, in making plans for any road improvement, shall cause such plans to be so prepared as to provide for the preservation of all cornerstones and landmarks set within the limits of the highway to be improved. All such cornerstones and landmarks shall be preserved or reset in their exact locations, and where located within the improved surface of the highway, the plans for the improvement shall be so drawn as to furnish adequate protection to such cornerstones and landmarks and also to furnish, by suitable devices or otherwise, full opportunity for consulting or referring to the same at any time, without destruction of or injury to the surface of the road improvement.
R.C. § 5519.05