SHIPPING WITHIN THE GREAT LAKES AND ALONG THE SEAWAY and the North Atlantic coast remains a huge business to this day, moving some 200 million tons per year of raw industrial materials like ore, sand, salt and chemicals. And much of it travels through the Seaway locks. But the overseas component of the Seaway’s traffic, which peaked at 23.1 million tons in the late 1970s, has dropped in some recent years to less than 6 million tons. Today overseas cargo typically accounts for about 5 percent or less of the overall Great Lakes and St. Lawrence Seaway shipping industry.
