The site was surveyed and mapped by E. G. Squier in 1847 for inclusion in the seminal archaeological and anthrolopological work Ancient Monuments of the Mississippi Valley. They described the earthwork as being a causewayed embankment 5 feet (1.5 m) high by 30 feet (9.1 m) wide encircling a ditch 6 feet (1.8 m) deep and 25 feet (7.6 m) across. They encircled an area 90 feet (27 m) in diameter. In the center of the ditch was a conical tumulus 8 feet (2.4 m) high and 40 feet (12 m) in diameter.[3]
Gallery
Squier and Davis illustration of the Biggs site
Squier and Davis map with Group D or the Biggs site
Scale aerial illustration of the Portsmouth Earthworks
^Applegate, Darlene (2008), "Chapter 5:Woodland period"(PDF), in Pollack, David (ed.), The Archaeology of Kentucky:an update, vol. 1, Kentucky Heritage Council, pp. 524–525, ISBN978-1-934492-28-4, archived from the original(PDF) on 2010-11-08 (author confused Biggs as being Group C, when it is in actuality Group D)