Shoot, I have that link laying around in one of my bookmark folders related to a book I'm working on. It's great! I should have added that to the notes but it's a little late now.

Thanks for the comment. I've been fascinated by this history since I was a kid collecting arrowheads in Illinois :-)

You'd be surprised to know how many I found just in the forest preserves south of Chicago. I lived just a few blocks from one as an elementary age kid. These days, parents probably wouldn't let their kids roam there alone, but I did all the time, hunting for the arrowheads, wanting desperately to understand who made them.