Hi, Robert I have my McLean Co. Atlas out and Mackinaw River flows just south of Lexington traveling southeast through Lexington Township. It heads southeast to Colfax and travels south of Anchor, IL , then east to Sibley, IL. I realize you were asking about Mackinaw Creek which may have existed in 1840's, maybe a branch heading northeast towards Belle Prairie or Indian Grove Twp., Livingston Co., IL. There used to be a thriving village southeast of Lexington named Pleasant Hill, now just a couple of houses, if that! Susan