The gravel in your driveway, the steel in your car, and the coal that produced electricity for your home may well have spent time on a Great Lakes freighter on its way to you. Each year, over 100 million tons of iron ore, coal, limestone and other products travel through the Great Lakes navigation system on ore ships.
Multimedia producer Allison Swaim takes us on board one of these ships: the MV Calumet. At 630 feet, it's longer than two football fields and holds close to 20,000 tons of cargo. You'd need almost 1,000 semi-trucks to carry the same load. Seventeen crew members live and work on the ship for a month at a time. It's a working boat, and the work never stops.