The Port of Detroit is located along the west side of the Detroit River and is the largest seaport in the state of Michigan:
The port consists of multiple marine terminals handling general, liquid, and bulk cargo as well as passengers. The Port of Detroit’s single most valuable commodity is steel, and the largest commodity handled by tonnage is ore. Other important commodities handled at the port include stone, coal and cement.
…Each year, the Port Authority oversees millions of tons of cargo at 29 private and public sector terminal facilities in the Port of Detroit. International and domestic high-grade steel products, coal, iron ore, cement, aggregate and other road building commodities are shipped in and out of Detroit’s port. It is the third largest steel-handling port in the nation.
More at the Port of Detroit website.