Earthworks of Eastern North America
Serpent Mound State Memorial, a Photo Gallery
Serpent Mound, one of the most noted effigy mounds in North America, is located on State Route 73 near Locust Grove, Adams County, Ohio. The earthwork winds along a ridgetop for about a quarter mile.
Serpent Mound Oval Mound

The serpent has a coiled tail at the upper end and open maws at the lower end, as if about to swallow the oval mound.

The oval mound has variously been interpreted as a egg and the sun about to be swallowed by an eclipse. The mound points in the direction of summer solstice sunset.

There are several interpretation signs.

Click images for larger views.

Serpent Mound Placemark File.
Includes Squier and Davis survey map overlay image and GPS positions.

Ancient Monuments Placemarks
includes more Squier and Davis
Ancient Monuments survey map
overlays for Hopewell sites.

Serpent Mound Ohio Historical Marker

The Serpent Mound Harvard Marker

Serpent Mound undulating across the landscape.

Archaeologists in 1991 opened a trench first cut by the Putnam excavaton in the late 1800s and recovered organic materials from the undisturbed edge of the trench. Radiocarbon dating placed construction at about 900 years ago, over a millenia later than once thought based on association with the nearby Adena burial mounds (image below).

Next below is the tail of the serpent with the GPS receiver along the west edge.

Serpent Mound's tail.Serpent Mound sits within an oblong crater where a massive extraterrestrial object collided with the earth. The crater overlaps Adams, Pike and Highland counties, and the mound is near the five-mile-across crater's southwest edge. The topography around Serpent Mound is jumbled, and impact theory explains why for many geologists. Boreholes samples show microscopic cracks in quartz crystals and horsetail-shaped fracture shatter cones, patterns resembling nuclear reactions. Iridium is high in the area.

One of the burial mounds near Serpent Mound.


Adena Burial Mound at Serpent Mound.

Serpent Mound GPS-determined coordinates.
Serpent Mound Burial Mound
Serpent Mound Oval Mound
Serpent Mound Tail

The Oval Mound at Serpent Mound is situated precisely one degree west of Newark Circle while the longitude difference with Newark Octagon equals circumference/365.

Serpent Mound Squier and Davis survey map.
Map reoriented to accurate north. Click for larger map.

Serpent Mound, a Photo Gallery PowerPoint

Sources and Bibliography

Squier, Ephriam G. and Edwin H. Davis 1847 Ancient Monuments of the Mississippi Valley. Smithsonian Institution, Washington, D. C.

Redating Serpent Mound Archaeology 49:6, Nov/Dec 1996

Bull, C., C. E. Corbato, J. C. Zahn 1967 Gravity Survey of the Serpent Mound Area, Southern Ohio, The Ohio Journal of Science 67(6):359-371.

©2006 by James Q. Jacobs.  All Rights Reserved.  Permissions.  Contact.

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