From Ohio History Central
Leo Petroglyph is located in Jackson County near Leo, Ohio. It is actually a series of petroglyphs, or rock carvings, ancient Indians chiseled into an outcropping of sandstone in southeastern Ohio.
The precise age of these carvings is unknown. Based on the symbolism and the amount of weathering of the generally soft sandstone, they probably are less than one thousand years old and so likely are the work of the Late Prehistoric period Fort Ancient culture, or the early Historic Indians.