There was a swamp on our farm the old timers told my grandfather that the Indians stoped at on there migration...sometime back about 1915 they hand dug tile and drained the swamp for farming....they found one of those grind stones. And it's in a yard in town now..I have tried to buy it but no luck yet...I did find one big point close to there it's about 2 1/2 inches long maybe a spear or knife type thing...