The Great Serpent Mound of Ohio, the Largest Earthen Effigy in the World

The Great Serpent Mound is a 1,300-foot (396 m) long and 3-foot (91 cm) high prehistoric effigy mound located on a plateau of a crater along Ohio Brush Creek in Adams County, Ohio, and is the largest surviving prehistoric effigy mound in the world. Resembling an uncoiling serpent, the mound is steeped in mystery and controversy. Despite over a century of research, there is no conclusive evidence about what it represents, when it was built, and what its true purpose was, though various astronomical alignments suggest it may have functioned as a type of calendar. Can we discern its significance?

The Unique Features and Historical Origins of the Serpent Mound

The Serpent Mound conforms to the curve of the land on which it rests, with its head approaching a cliff above a stream.  It winds back and forth for more than eight hundred feet and has seven distinct coils, ending in a triple-coiled tail. The serpent head has an open mouth extending around the east end of a 120-foot-long (36.57 m) hollow oval feature, which is generally viewed as an egg, although other interpretations suggest it is the sun, the body of a frog, or merely the remnant of a platform. To the west of the effigy, is a triangular mound measuring approximately 32 feet (9.75 m) at its base and long axis.  The Serpent Mound is believed to have been laid out all at once, with a layer of clay and ash, and reinforced with stones.

A digital GIS map of Ohio's Great Serpent Mound, created by Timothy A. Price and Nichole I., 2002.  (CC BY-SA 3.0)

Thousands of years ago, Native American peoples populated the Ohioan landscape with mounds and massive earthworks. Initial research attributed the effigy to the Adena culture, which flourished from 1000 BC to 100 AD.  The Adena culture are well-known for building burial and effigy mounds, many of which are located near the Great Serpent Mound.  However, radiocarbon dating on pieces of charcoal found within the Serpent Mound established that people worked on the mound around 1070 AD.  Thus, the mound may have been built by the Fort Ancient peoples, who lived in the Ohio Valley from 1000 to 1550 AD.  Nevertheless, the testing is not conclusive as it only reveals that 1000-year-old charcoal was found within the mound. This could have ended up there long after the effigy was originally built.

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Interpretations of the Serpent Mound

The most predominant theory is that the Serpent Mound represents a giant snake, which is slowly uncoiling itself and about to seize a huge egg within its extended jaws. However many theories abound suggesting various interpretations. For instance, some think it may represent an eclipse, or the phases of the moon. Others have speculated that it represents the myth of the horned serpent found in many Native American cultures. In 1909, local German Baptist minister Landon West proposed another unusual theory: the serpent was writhing in its death throes as punishment for tempting Adam and Eve in what West believed was the original Garden of Eden.

There are serious suggestions that the serpent is intimately connected with the heavens. Several writers have suggested that the serpent is a model of the constellation we call the Little Dipper, its tail coiled about the North Star.

Various alignments of the serpent correspond to astronomical features, such as alignments of the sun and moon. In 1987 Clark and Marjorie Hardman published their finding that the oval-to-head area of the serpent is aligned to the summer solstice sunset, suggesting that one of the effigy’s purposes was to mark the turning of the year so that planting and gathering and hunting could be planned.

William F. Romain has suggested an array of six lunar alignments corresponding to the curves in the effigy's body. If the Serpent Mound were designed to sight both solar and lunar arrays, it would be reflect the consolidation of astronomical knowledge into a single symbol.

View of the The Great Serpent Mound, one of the most important prehistoric effigy mound of Adena Culture, located on the Ohio River, USA.  (Timothy A. Price and Nichole I. /CC BY-SA 3.0)

Generations of researchers agree with the theory that the Serpent Mound holds astronomical significance, but the intent of those who built the serpent, and how it was used still remains a mystery. 

Many scholars believe the Serpent Mound was used in religious ceremonies. When settlers first discovered the mound, there was a fire-scorched stone monument in the egg-shaped head, which has led some to suggest it was used as an altar of some sort – possibly sacrificial, based on the ceremonial knives unearthed among the blackened stones and a number of headless skeletons discovered in gravesites nearby.

Whatever its true purpose, the Serpent Mound attests to the ingenuity of its creators. As the Ancient Ohio Trail website so aptly states: “The genius of its designers remains apparent: this blend of beauty, familiarity, abstraction, power, precision, and mystery, make Ohio’s Serpent Mound one of the great, iconic images for all of human antiquity.”

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Pathway to Prestige

Standing the test of time, Serpent Mound has encountered its share of difficulties. Over many centuries, it confronted deterioration due to natural elements and human actions. Fortunately, through the unyielding efforts of archaeologists and conservationists, the mound was safeguarded and designated as a National Historic Landmark in 1964.

In 2008, the U.S. Department of the Interior included Serpent Mound, alongside other Native American earthworks in Ohio, on the United States’ tentative list of sites for submission to UNESCO (the United Nations Educational, Scientific, and Cultural Organization). This submission aims for inclusion on the esteemed list of World Heritage Sites. Should the inscription proceed, which may occur in 2023 as projected by Jennifer Aultman, the World Heritage Director at Ohio History Connection, Serpent Mound will become part of the honoured collection of World Heritage Sites.

Top image: The Serpent Mound. Source: Vicki Timman/CC BY-ND 2.0

By Joanna Gillan

References

Arc of Appalachia Preserve System. Serpent Mound. Available at: https://www.arcofappalachia.org/visit/serpent-mound.html

Indian Country Media Network. Crazy Theories Threaten Serpent Mound, Demean Native Heritage. Available at: http://indiancountrytodaymedianetwork.com/2013/06/06/crazy-theories-threaten-serpent-mound-demean-native-heritage-149733

Ohio Historical Society. Serpent Mound –Available at: https://www.ohiohistory.org/museums-and-historic-sites/museum--historic-sites-by-name/serpent-mound

The Ancient Ohio Trail. Serpent Mound, the World’s Most Famous Earthen Effigy. Available at http://www.ancientohiotrail.org/?q=serpentmound_temp

The Metropolitan Museum of Art. 2002. Heilbrunn Timeline of Art History Great Serpent Mound. Available at:  https://www.metmuseum.org/toah/hd/serp/hd_serp.htm