This is one of many earthworks in the eastern and central parts of the United States. For a long time, white historians and antiquarians believed these the work of a vanished people, “the Moundbuilders,” separate from the various indigenous peoples living in the areas. The white historians and antiquarians were wrong, and now the historical establishment agrees with the indigenous that these were the work of their ancestors. Sadly, too many were destroyed as Europeans built their own works across the land. Some survive, such as this. Ohio History Connection currently runs it as a museum.
I visited there last summer, on (then) lovely day (it rained later. A lot. Plus thunder and lightning, which made my mother’s dog, traveling with us, very unhappy). At that time, the museum operators were keeping the mound mowed. I’ve heard since that they’re reconsidering this–but have yet to get back.
There’s a viewing station from which one can see most/all of the earthwork. It helps if you don’t mind heights or see-through stairs. There’s a walk around, but folks are (understandably) requested to keep off the actual mound.
It’s not clear just how old it is, but other mounds nearby date to 800 B.C.E. to 100 C.E. so it’s probably from somewhere in that range.
Here are a few more photos from my visit, closer up to various portions of the serpent.