From Archie Eschborn’s book, The Dragon in the Lake, regarding Tyranena in Wisconsin near Lake Mills, Wisconsin:
The Menomonee oral tradition is a clear tribal memory, spanning not centuries but millennia. It preserves their ancestors’ encounter 4,000 years ago with the fair-skinned seafarers from ancient Europe, who turned into aggressive copper miners in America. The Menomonee go on to tell that these foreign “Marine Men” were virtually exterminated in a series of bloody clashes with native warriors after the collapse of the ancient copper trade, leaving the European enterprises stranded in the great Lakes region, where they mostly fell victim to local uprisings. The survivors intermarried with indigenous tribes.
-Archie Eschborn, The Dragon in the Lake , page 29.