> Illinois River Photo Gallery

« Back to Illinois River Photo Gallery

Lower Illinois River Valley

Lower Illinois River Valley

Illinois River Road, Greene County

Limestone cliffs capped with loess (a fine wind-blown soil) characterize much of the Illinois River valley downstream from Scott County. The bluff at this location is adjacent to the former Koster Site, one of the most important archaeological digs in North America. From evidence gathered through extensive excavations over many years, scientists have determined that humans have occupied this particular site for over 7,000 years.