“…In the central Illinois River valley, small, dispersed settlements and the use of crypt-ramp burial mounds appear by the last century BCE (Struever, 1965(Struever, , 1968Ruby et al, 2005). By approximately 50 BCE, settlement expanded south into the largely unoccupied lower Illinois river valley, as evidenced by the bluff-top mound groups that were constructed in a generally north to south chronological trend over several hundred years (Buikstra and Charles, 1999;Ruby et al, 2005;King et al, 2011;Herrmann et al, 2014;Farnsworth and Atwell, 2015, p. 199).…”