The Detroit River is about 51 km (32 miles) long and 1 to 4 km (0.5 to 2.5 miles) wide in the Great Lakes system. It flows from Lake St. Clair to Lake Erie. The boundary between Canada and the United States of America passes through the river lengthwise. Its elevation is 175 meters above sea level.
Islands in the Detroit River include Peche Island, Belle Isle, Zug Island, Fighting Island, Grosse Ile, and Bois Blanc (a.k.a. Boblo) Island. The islands of the lower Detroit River are part of the Detroit River International Wildlife Refuge. It is spanned by the Ambassador Bridge and two tunnels connecting Detroit, Michigan and Windsor, Ontario, one for cars and one for trains. Two bridges connect Grosse Ile to the mainland USA and one bridge connects Belle Isle to Detroit.
The Detroit River supplies the drinking water for over 5 million people and was designated an American Heritage River in 1998. A shipping channel for the Great Lakes Waterway system is maintained in the river.
The river flows past the U.S. towns of Detroit, River Rouge, Wyandotte, Grosse Ile, Riverview, Trenton, and Gibraltar. It flows past the Canadian towns of Windsor, Amherstburg, and Lasalle.