Serpent Mound is a spectacular effigy earthwork of a serpent uncoiling along a prominent ridgetop in northern Adams County, Ohio. From the tip of its nose to the end of its tail, the effigy is 1,427 feet long. When it was originally described, in 1848, the body of the serpent was five feet high and 25 feet wide.
Excavations between 1887 and 1889 by Frederic Putnam, of Harvard University's Peabody Museum, revealed the structure of the earthwork. But Putnam did not find any artifacts inside the mound that would reveal the age or cultural affiliation of the mound. Until recently, archaeologists assumed that Serpent Mound was built by the Adena culture since two Adena burial mounds are located nearby. The Adena culture dates from between 800 B.C. and A.D. 100. However, there is also a Fort Ancient culture burial mound at the site. The Fort Ancient culture dates from between A.D. 1000 and A.D. 1650. Putnam also discovered traces of a village of the Fort Ancient culture overlying a smaller Adena site just south of the Serpent. Excavations into the Serpent in 1991 recovered charcoal that returned radiocarbon dates suggesting that the Fort Ancient people built the mound between about A.D. 1025 and A.D. 1215.
Serpents are a common feature in the art of the Late Prehistoric Period (A.D. 900 C.E. to A.D. 1650). Many American Indians of the Eastern Woodlands believed the Great Serpent was a powerful spirit of the Underworld. Serpent Mound may be a representation of these beliefs..
The head of Serpent Mound is aligned to the setting sun on the summer solstice and the coils may be aligned to the summer and winter solstice and equinox sunrises. These alignments support the idea that Serpent Mound had a ceremonial purpose.
Frederic Putnam saved Serpent Mound from destruction. On his urging, funds were raised for Harvard University to purchase the site. The Peabody Museum converted the property into a public park and operated it as such until 1900, when it was deeded to the Ohio State Archaeological and Historical Society, now the Ohio History Connection. In 1908, an observation tower was built and during the 1930s a museum and other visitor facilities were added.
Serpent Mound is recognized as a National Historic Landmark. Serpent Mound State Memorial is located 20 miles south of Bainbridge in Adams County.
- Squier, Ephraim George, and Edwin Hamilton Davis. Ancient Monuments of the Mississippi Valley: Comprising the Results of Extensive Original Surveys and Explorations. Washington, DC: Smithsonian Institution, 1848.
- Putnam, F. W., The Serpent Mound of Ohio. Century Magazine 39:871-888, 1890.
- Lepper, Bradley T., Great Serpent. Timeline 15(5):30-45, 1998.
- Lepper, Bradley T., Ohio's "Alligator." Timeline 18(2):18-25.
- Lepper, Bradley T., Ohio's Archaeology: An Illustrated Chronicle of Ohio's Ancient American Indian Cultures. Wilmington, Ohio: Orange Frazier Press, 2005.
- Glotzhober, Robert C. and Bradley T. Lepper, Serpent Mound: Ohio's Enigmatic Effigy Mound. Ohio History Connection, 1994.
- Fletcher, Robert, Terry Cameron, Bradley T. Lepper, Dee Anne Wymer, & William Pickard, "Serpent Mound: a Fort Ancient Icon?" Midcontinental Journal of Archaeology 21(1)105-143, 1996.