Detroit River

The Detroit River is an international river in North America. The river, which forms part of the international border between the U.S. state of Michigan and the Canadian province of Ontario, flows west and south for 24 nautical miles (28 mi; 44 km) from Lake St. Clair to Lake Erie as a strait in the Great Lakes system. The river divides the metropolitan areas of Detroit, Michigan, and Windsor, Ontario—an area collectively referred to as Detroit–Windsor. The Ambassador Bridge, the Detroit–Windsor Tunnel, and the Michigan Central Railway Tunnel connect the cities.

The river's English name comes from the French Rivière du Détroit (translated as "River of the Strait"). The Detroit River has served an important role in the history of Detroit and Windsor, and is one of the world's busiest waterways. It is an important transportation route connecting Lake Michigan, Lake Huron, and Lake Superior to Lake Erie and eventually to Lake Ontario, the St. Lawrence Seaway and the Erie Canal. When Detroit underwent rapid industrialization at the turn of the 20th century, the Detroit River became polluted and toxic. Since the late 20th century, however, a vast restoration effort has been undertaken because of the river's ecological importance.