Journal of Astronomy in Culture

The Mississippian-era site of Cahokia was the largest Native American city north of Mexico. Archaeologists have long speculated about possible astronomic alignments and spatial relationships in the layout of its 100+ earthen mounds. In this paper LiDAR imagery, historic documents, ethnohistoric and archaeologic data are used to assess the site relative to astronomic and landscape alignments. New findings show how Monks, Rattlesnake, Powell and other mounds are aligned to the Sun, Moon, and Milky Way. Additionally, these alignments intersect prominent bluffs to the east and southeast that appear to have been used as horizon markers.