In 1883, Frederick Ward Putnam of Harvard University first visited the Serpent, and began a successful campaign to buy and restore it. Harvard gave the Serpent Mound to the State of Ohio in 1900, and today it remains a State Memorial open to the public, and managed by staff and volunteers of the Arc of Appalachia Preserve System.

Carbon dates have shown that the Great Serpent was probably built by people of the “Fort Ancient” tradition, who followed centuries after the Hopewell. The two Adena mounds indicate this site was important for centuries before the effigy was built in about AD 1100. Indeed long before humans were here at all, the vicinity of Serpent Mound was a geological anomaly, likely the result of a primordial meteor strike or subterranean explosion. The serpent’s head looks out over the western rim of this 4-mile wide formation