Ohio Revised Code Title LV. Roads Highways Bridges § 5516.061

(A) No advertising device shall be erected outside of urban areas further than six hundred sixty feet from the right-of-way of the main traveled way of a highway on the interstate or primary system if such device would be visible from such main traveled way, except signs lawfully in existence on October 22, 1965, that the director of transportation, subject to the approval of the secretary of the United States department of transportation, has determined to be landmark signs, including signs on farm structures or natural surfaces that are of historic or artistic significance.

(B) Any advertising device lawfully in existence prior to November 28, 1975, or lawfully on any highway made a part of the interstate or primary system on or after that date, the erection of which would be illegal under this section, is nonconforming, and may be maintained subject to the permit provisions of section 5516.10 of the Revised Code. An advertising device existing prior to September 16, 2004, which would be illegal under this section shall be considered a nonconforming advertising device and may be maintained subject to the permit provisions of section 5516.10 of the Revised Code.

(C) As used in this section, “urban area” means an urbanized area or an urban place as designated by the bureau of the census having a population of five thousand or more, and within boundaries approved by the United States secretary of transportation.