The Valparaiso Moraine is a terminal moraine that forms an immense U around the Lake Michigan basin in North America. It is a band of high, hilly terrain made up of glacial till and sand. It begins near the border of Wisconsin and Illinois and extends south through Lake, McHenry, Cook, DuPage and Will counties in Illinois, and then turns southeast, entering Indiana. From this point, the moraine curves northeast through Lake, Porter, and LaPorte counties of Indiana into Michigan. It continues into Michigan as far as Montcalm County.