channel connecting Lakes Michigan (Michigan, Lake) (west) and Huron (Huron, Lake) (east) and forming an important waterway between the Upper and Lower peninsulas of Michigan, U.S. Spanned by the Mackinac Bridge (opened 1957) and underwater gas and oil pipelines, the straits are 4 miles (6 km) wide and approximately 30 miles (50 km) long and include the passage between several islands in northwestern Lake Huron. Discovered by Jean Nicolet (Nicolet, Jean) in 1634, the straits played a prominent role in the fur trade and defense of the upper Great Lakes and Canada.