the lake superior lowland is defined by a plain that slopes gently downward towards the north. while the area is mostly flat, the altitude ranges from about 600 feet (180 m) to 1000 feet (or 300 meters) above sea level. the higher altitudes are located on the bayfield peninsula, where the characteristic plain gives way to more rugged hills. northeast of the peninsula are the apostle islands, which have been designated as a national lakeshore.