Storied: Split Rock Lighthouse, Part 1 of 8 Split Rock Lighthouse opened in the summer of 1910 to guide bulk ore ships sailing near Lake Superior's rocky coast. By 1940, its picturesque North Shore setting had made it one of the most visited lighthouses in the United States. In the early years of the 20th century, iron ore shipments on Lake Superior doubled and redoubled. United States Steel's bulk ore carriers became "the greatest exclusive freight-carrying fleet sailing under one ownership in