Radiocarbon Dates Reveal Serpent Mound Is More than Two Thousand Years Old

Recent radiocarbon dating (Herrmann et al. 2014) found that Serpent Mound was likely built during the Early Woodland period—around 320 BC. Herrmann et al. (2014) also suggested that the effigy was repaired or restored during Fort Ancient times, thereby accounting for the late prehistoric radiocarbon-dated samples recovered by Fletcher et al. (1996). The present article presents new data in support of the Early Woodland construction date. These data include lidar analyses, electrical resistivity ground imaging (ERGI) studies, and iconographic assessments.