Cahokia, an interesting book

Cahokia : ancient America's great city on the Mississippi--by Pauketat, Timothy R.

New York : Viking Penguin, 2009. ISBN:  9780670020904 0670020907  the site of an ancient indigenous city (650–1400 CE) near Collinsville, Illinois. In the American Bottom floodplain, it is across the Mississippi River from St. Louis, Missouri. The 2,200-acre (8.9 km2) site included 120 man-made earthen mounds over an area of six square miles, although only 80 survive.[1] A small volume in size with just under 200 pages with maps.  It discusses  theories about the great city of the mound builders. available on loan from the Barrie Public Library