It’s the largest lake in the world, a body of fresh water so vast it creates its own climate and supports thousands of residents along its shores. Lake Superior straddles the U.S.-Canadian border, the two nations separated on the east side by a busy portage canal. The lake’s icy waters harbor a remote national park, Isle Royale, an island large enough to support a lake with its own island. Long before the arrival of Europeans, Lake Superior was home to vibrant cultures and vigorous trade in copper. The Canadian shores feature seemingly unending forests and some of the coldest towns in the Americas.