Ground Truthing The Great Circle and other Big Data Anomalies at the Hopewell Mound Group

Author(s): Bret Ruby

Year: 2016


The monumental mounds and earthworks at Hopewell Mound Group have attracted attention since the dawn of American archaeology. By the early 20th century, the site’s imposing earthworks, exotic raw materials, and exquisitely crafted artifacts were widely recognized as the most flamboyant expression of a newly defined “Hopewell culture.” Yet attention was focused narrowly on mounds and mortuary contexts, ignoring the vast spaces in between. Agricultural plowing steadily eroded above-grade features. Today, most visitors experience the site as a featureless plain. However, recent large-scale geomagnetic surveys successfully documented the subsurface integrity of many plowed-down mounds and earthworks, and revealed a host of anomalies both large and small filling the spaces between the monuments. This presentation describes the results of two seasons of targeted excavations intended to ground truth several intriguing anomalies. One focused on the “Great Circle,” a circular earthwork nearly 120 meters in diameter thought to have been entirely obliterated by plowing before 1891. Our excavations revealed a deep encircling ditch flanked on the interior by a row of deep pits that likely supported huge wooden posts – an enormous Hopewell “woodhenge.” The second season revealed a gigantic but enigmatic pit feature with an estimated volume approaching 15 cubic meters.

Cite this Record

Ground Truthing The Great Circle and other Big Data Anomalies at the Hopewell Mound Group. Bret Ruby. Presented at The 81st Annual Meeting of the Society for American Archaeology, Orlando, Florida. 2016 ( tDAR id: 404358)


Spatial Coverage

min long: -104.634; min lat: 36.739 ; max long: -80.64; max lat: 49.153 ;