1933 Dasche Reeves aerial photo of central Cahokia area (Monks Mound at top with Grand Plaza in middle) with arrows pointing to faint light lines that indicate the former location of a wooden palisade.

Anderson, J. 1969. A Cahokia Palisade Sequence. In Explorations in Cahokia Archaeology, edited by M. L. Fowler, pp. 89-99. . Illinois Archaeological Survey, Bulletin No. 7. Fig. 44

Image courtesy of the Illinois Archaeological Survey.