Fort Ancient Culture: Great Serpent Mound

The Great Serpent Mound in rural, southwestern Ohio is the largest serpent effigy in the world. Numerous mounds were made by the ancient Native American cultures that flourished along the fertile valleys of the Mississippi, Ohio, Illinois, and Missouri Rivers a thousand years ago, though many were destroyed as farms spread across this region during the modern era. They invite us to contemplate the rich spiritual beliefs of the ancient Native American cultures that created them.

The Great Serpent Mound measures approximately 1,300 feet in length and ranges from one to three feet in height. The complex mound is both architectural and sculptural and was erected by settled peoples who cultivated maize, beans and squash and who maintained a stratified society with an organized labor force, but left no written records. Let’s take a look at both aerial and close-up views that can help us understand the mound in relationship to its site and the possible intentions of its makers.

​The serpent is slightly crescent-shaped and oriented such that the head is at the east and the tail at the west, with seven winding coils in between. The shape of the head perhaps invites the most speculation. Whereas some scholars read the oval shape as an enlarged eye, others see a hollow egg or even a frog about to be swallowed by wide, open jaws. But perhaps that lower jaw is an indication of appendages, such as small arms that might imply the creature is a lizard rather than a snake. Many native cultures in both North and Central America attributed supernatural powers to snakes or reptiles and included them in their spiritual practices. The native peoples of the Middle Ohio Valley in particular frequently created snake-shapes out of copper sheets.

The mound conforms to the natural topography of the site, which is a high plateau overlooking Ohio Brush Creek. In fact, the head of the creature approaches a steep, natural cliff above the creek. The unique geologic formations suggest that a meteor struck the site approximately 250-300 million years ago, causing folded bedrock underneath the mound.

Aspects of both the zoomorphic form and the unusual site have associations with astronomy worthy of our consideration. The head of the serpent aligns with the summer solstice sunset, and the tail points to the winter solstice sunrise. Could this mound have been used to mark time or seasons, perhaps indicating when to plant or harvest? Likewise, it has been suggested that the curves in the body of the snake parallel lunar phases, or alternatively align with the two solstices and two equinoxes.

Some have interpreted the egg or eye shape at the head to be a representation of the sun. Perhaps even the swallowing of the sun shape could document a solar eclipse. Another theory is that the shape of the serpent imitates the constellation Draco, with the Pole Star matching the placement of the first curve in the snake’s torso from the head. An alignment with the Pole Star may indicate that the mound was used to determine true north and thus served as a kind of compass.

Of note also is the fact that Halley’s Comet appeared in 1066, although the tail of the comet is characteristically straight rather than curved. Perhaps the mound served in part to mark this astronomical event or a similar phenomenon, such as light from a supernova. In a more comprehensive view, the serpent mount may represent a conglomerate of all celestial knowledge known by these native peoples in a single image.

Determining exactly which culture designed and built the effigy mound, and when, is a matter of ongoing inquiry. A broad answer may lie in viewing the work as being designed, built, and/or refurbished over an extended period of time by several indigenous groups. The leading theory is that the Fort Ancient Culture (1000-1650 C.E.) is principally responsible for the mound, having erected it in c. 1070 C.E. This mound-building society lived in the Ohio Valley and was influenced by the contemporary Mississippian culture (700-1550), whose urban center was located at Cahokia in Illinois. The rattlesnake was a common theme among the Mississippian culture, and thus it is possible that the Fort Ancient Culture appropriated this symbol from them (although there is no clear reference to a rattle to identify the species as such).

An alternative theory is that the Fort Ancient Culture refurbished the site c. 1070, reworking a preexisting mound built by the Adena Culture (c.1100 B.C.E.-200 C.E.) and/or the Hopewell Culture (c. 100 B.C.E.-550 C.E.). Whether the site was built by the Fort Ancient peoples, or by the earlier Adena or Hopewell Cultures, the mound is atypical. The mound contains no artifacts, and both the Fort Ancient and Adena groups typically buried objects inside their mounds. Although there are no graves found inside the Great Serpent Mound, there are burials found nearby, but none of them are the kinds of burials typical for the Fort Ancient culture and are more closely associated with Adena burial practices. Archaeological evidence does not support a burial purpose for the Great Serpent Mound.

Whether this impressive monument was used as a way to mark time, document a celestial event, act as a compass, serve as a guide to astrological patterns, or provide a place of worship to a supernatural snake god or goddess, we may never know with certainty. One scholar has recently suggested that the mound was a platform or base for totems or other architectural structures that are no longer extant, perhaps removed by subsequent cultures. All to say, scholarly debate continues, based on on-going archaeological evidence and geological research. But without a doubt, the mound is singular and significant in its ability to provide tangible insights into the cosmology and rituals of the ancient Americas.

Essay by Katherine T. Brown