Serpent Mound probably built about 800 years after the Hopewell-era sites) is the largest documented surviving example of an ancient effigy mound in the world. While part of the tradition of effigy building among some American Indian cultures in what is now the eastern United States, this site is the greatest masterpiece of that tradition both here and elsewhere in the world. The sinuous, artistically-striking monumental sculpture is more than 1,200 feet long. Its scale and elegance are without peer. It embodies fundamental spiritual and cosmological principles that still resonate with many today, including astronomical alignments that mark the seasons.
Serpent Mound State Memorial encompasses the monumental Serpent Mound as well as three burial mounds and associated habitation sites. The sinuous earthen embankment culminates in a 37 by 18 m oval embankment at the northwest end, which has been interpreted variously as the serpent’s eye, part of its head, or a secondary object, such as an egg, grasped in the serpent’s open jaws. The effigy ranges from 1.2 to 1.5 m in height and from 6 to 7.6 m in width. The best available evidence, including radiocarbon dates and analyses of the iconography, indicates Serpent Mound was built by the Fort Ancient Culture at approximately AD 1120.
Serpent Mound was first documented in 1848 by Ephraim Squier and Edwin Davis in Ancient Monuments of the Mississippi Valley, the first publication of the Smithsonian Institution. Frederic Ward Putnam, of Harvard University’s Peabody Museum, was instrumental in raising funds to purchase the property and, in 1887, the Peabody Museum acquired the site. From 1887 to 1889, Putnam conducted systematic investigations of portions of the effigy, the adjacent burial mounds, and parts of the surrounding landscape. After concluding his research, he carefully restored the mounds.
The Peabody Museum converted the property into a public park and operated it as such until 1900, when it was deeded to the Ohio Archaeological and Historical Society (more recently the Ohio Historical Society, now the Ohio History Connection). In 1908, an observation tower was built and during the 1930’s a museum and other visitor facilities were added.