In the impact crater of a giant meteor, an unknown ancient race built the largest snake effigy on the planet… Is this the beginning of a lurid sci-fi fantasy novel? No, it’s the description of an actual place.  This haunting structure which was built for unknown reasons by a mystery race can be found in deepest…um…Ohio!

The Great Serpent Mound is an ancient earthwork located in Adams County, Ohio.  Shaped like a snake devouring an egg, the mound is 410 meters (1,330 feet long) and a meter tall (3 feet).  The undulating form of the snake has been tied to astronomical phenomena but it is unclear why it was built or what purposes (if any) it served. It reminds me somewhat of the Rainbow Serpent, Wadjet, Nüwa, and other snake deities, but since there is no historical or ethnological record of its purpose, such connections are only airy speculation.

Possible Astronomical Significance of the Great Serpent Mound

An even greater mystery of the structure is who built it. Over the years scholars and archaeologists have variously posited that it was created by the Adena culture (1000 to 200 BC), or by tribes from the Hopewell tradition (200 BC to 500 AD), or by the Fort Ancient culture (1000 AD-1750 AD).  Of course the mound was known long before its “discovery” by European settlers. Unfortunately, the Native Americans of the region seemed just as confused about its provenance as anyone. For what it is worth, Native Americans of the Lenni Lenape (later Delaware) nation told missionaries that the mound was built by the Allegheny or Allegewi People, (who were also sometimes called the Tallegewi), a possibly mythical progenitor race who lived in the Ohio Valley in ancient times before 1200 BC.

The Great Serpent Mound from the Air

It is obvious that a date is thoroughly confused when it varies by as much as 3,000 years! Fortunately there are a few pieces of actual evidence associated with the mound. Adena graves were found and excavated near the Serpent Mound (Adena people were culturally and physically distinct from other peoples of the Ohio valley). Other Adena sites have revealed that these peoples built elaborate circular and winding earthworks and had a fascination with astronomical phenomena. The few pieces of Aedena art even seem to bear an aesthetic connection.

A Serpent Carved from Micah by the Adena or Hopewell

Frustratingly, carbon dating of charcoal taken from within the mound seems to indicate that it was built (or at least refurbished) long after the Adena culture declined and vanished. Conducted in the nineteen nineties, these tests indicated that parts (or all) of the Serpent Mound was built around 1070 AD.  The mound would thus have been made by people of the Fort Ancient Culture–but the Fort Ancient people do not seem to have evinced the same artistic and cosmological sensibilities as are reflected in the mound.  Additionally the mound was uncharacteristic of Fort Ancient culture in its lack of buried valuables.

A painting of Fort Ancient Civilization

Charcoal fragments are easily displaced by bioturbation and burrowing animals, so the carbon dating stands in question. The Fort Ancient people are known to have had contact with the intense pyramid building, city-dwelling (serpent worshipping) Mississippian cultures which were flourishing from Illinois down to the Gulf of Mexico. Perhaps outside cultural influences lead to the mound’s construction. Furthermore the Fort Ancient people got their name from the fact that they lived on huge earthworks built by the vanished Hopewell people (who are also potential builders of the Great Serpent Mound). Perhaps the Fort Ancient tribes also renovated and re-purposed the Great Serpent Mound from older Adena or Hopewell builders.  We simply are not certain about who crafted the Great Serpent Mound–but it is to be hoped that further evidence will clarify the issue.

By now space enthusiast readers are probably chaffing at all of this human history: in the first paragraph I mentioned that the Great Serpent Mound is located in a meteor impact crater. relates how the crater was discovered by scholars studying the Great Serpent Mound:

After the mound was discovered it was noticed that the geology of the surrounding area differed greatly from that found elsewhere in Ohio. John Locke, who explored the area in the 1830’s noted that “a region of no small extent had sunk down several hundred feet, producing faults, dislocations and upturnings of the layers of the rocks.” At the time he thought the he had discovered a “sunken mountain.” Some of the areas look like they have slid straight down while others have risen almost 1,000 feet straight up. Over time more evidence has been found. Eventually in the 1970’s, core samples were taken from the crater area. Scientists have found iridium at levels up to 10 times that normally found in the Earth’s crust, soot from what may be scorched limestone, deformed grains of sand, and quartz with microscopic fractures. In addition “shatter cones” have been found from the surface down similar to those found in Nevada at nuclear weapon test sites.  

Such features are the smoking gun evidence of meteor strikes and scientists have since concluded that the crater is about 250 million years old (which was approximately the same era the Paleozoic came to an end). Over a quarter of a billion years the crater has deformed greatly, to such an extent that it is not immediately recognizable (unlike more contemporary strike sites such as Lake Lonar).