From Ohio History Central
Petroglyphs are a form of rock art in which the image is carved, cut, chiseled, or pecked into the rock. They are distinguished from pictographs, which are images that are painted or drawn onto rock surfaces.
Ohio's two most famous petroglyph sites are Inscription Rock and Leo Petroglyph, but there were many others. Ohio's petroglyphs may vary in age from thousands to hundreds of years old, but since most of Ohio's rocks are soft sandstones and limestones, older petroglyphs will have been slowly erased by the actions of rain and wind. Only if the petroglyphs are in a protected location, such on the walls of a cave or rockshelter, will truly ancient carvings have been preserved.
Most of Ohio's documented petroglyphs belong to the Late Prehistoric Period. The symbols that commonly appear in petroglyphs often are typical of symbols found in other Late Prehistoric art and which still are recognized and used by many American Indian tribes of the Eastern Woodlands. Many of these relate to spiritual beliefs, such as Thunderbirds, Underworld Serpents, and shamans with horns or antlers that indicate their spiritual power.
In early historic times, symbols such as those carved onto rock walls also were carved and painted on the trunks of trees or on sheets of bark mounted on poles. It is likely that Ohio