Bois Blanc Island (Ontario)

Bois Blanc Island, commonly called Boblo Island, is an island in the Detroit River on the Canadian side of the border and is part of Amherstburg, Ontario. The island is about 2.5 miles (4 km) long, 0.5 mile (0.8 km) wide and 272 acres (110 ha) in size.

The main north-bound shipping channel of the Detroit River currently lies between Bois Blanc Island and the Amherstburg mainland. A stone lighthouse built in 1836 on the southern tip of the island marks the historical beginning of the Detroit River navigation channel for ships traveling upriver from Lake Erie.

Bois Blanc means "White Woods," a name derived from the many birch and beech trees in the area. "Boblo" is an English corruption of the French pronunciation of the name. Several islands with the same name dot the Great Lakes, and nearly all are known as "Boblo" or "Bob-lo" by the local populations.

The island gained strategic importance when Fort Amherstburg (now Fort Malden) was built in 1796 to guard passage along the Detroit River after Detroit was turned over to the Americans. Guns from the fort could reach the island across the navigable waters and hence secured the river.