McQuade Small Craft Harbor is a prime place to watch interlake and ocean-going freighters known as salties, along with workboats, fishing boats, and recreational craft of many kinds. Duluth-Superior Harbor, the largest inland port in the United States, receives more than 1,000 freighters each year. Great Lakes and foreign cargoes include iron ore, coal, limestone, salt, cement, grain, steel, and machinery. The largest ships on the Great Lakes are more than 1,000 feet long and carry 70,000 tons. Paddlers also use the Lake Superior Water Trail, a well-charted route with many access points and camping opportunities along Minnesota's North Shore.