I am from Ohio and we do find some good flakey gold here and there. Get a map of glaciation of Illinois and concentrate on streams that disect Illinioan terminal moraines. Here in Ohio and southern Indiana, those seem to produce best. If you can get to bedrock in these streams, all the better. The cracks and potholes catch the gold. The Illinioan moraines produce better, becuase the they scraped off the better gold producing rock from Canada first. Chuck Lasseter has a good book out (Midwest Gold Prospecting). Well worth the low cost and great reading. I might be able to locate a map I had once and will post if I can find it. Hope this helps some...