Serpent Mound is an internationally known National Historic Landmark built by the ancient cultures of Ohio. It is an effigy mound (a mound in the shape of an animal) representing a snake with a curled tail. Nearby are three burial mounds – two created by the Adena Culture (800 BC-100 AD), and one by the Fort Ancient Culture (1000-1650 AD). The Serpent Mound has no associated burials and was likely used for ceremonial purposes.
Thousands of years ago Native Ohioans populated the landscape with mounds and massive earthworks. In the late nineteenth century, Harvard University archaeologist Frederic Ward Putnam excavated Serpent Mound, but he found no artifacts in the Serpent that might allow archaeologists to assign it to a particular culture. Based largely on the nearby presence of Adena burial mounds, later archaeologists attributed the effigy to the Adena culture that flourished from 800 B.C. to A.D. 100.This theory on the site’s origin was accepted until a 1991 site excavation used radiocarbon dating to determine that the mound was approximately 900 years old. This would suggest the builders of the Serpent belonged to the Fort Ancient culture (A.D. 1000-1500). In 2014, another team of archaeologists presented new radiocarbon dates for the Serpent suggesting it was built by the Adena culture at around 300 B.C.. More work is needed to clarify the age of Serpent Mound.
The significance of Serpent Mound and other ancient Ohio earthworks has garnered international attention. In 2008, Serpent Mound and eight other Ohio earthworks were selected by the United States Department of the Interior for inclusion on the United States’ Tentative List of sites to be submitted to United Nations Educational, Scientific, and Cultural Organization (UNESCO) for inscription on the prestigious World Heritage List. If it is eventually inscribed on the World Heritage List later this decade, Serpent Mound will join the ranks of the Pyramids of Egypt, the Great Wall of China, Pompeii, Stonehenge, and the Taj Mahal—all of which are World Heritage sites. World Heritage status has the potential to elevate local and international awareness about the site's value, further encourage communities to protect and invest in their preservation and increase potentially beneficial tourism to the site.
Serpent Mound is managed locally by the Arc of Appalachia Preserve System.