STS068-209-067 Straits of Mackinac, Michigan, U.S.A. October 1994 Apparent in this northeast-looking, low-oblique, color infrared photograph are northern lower Michigan and the Straits of Mackinac, a passage between the Upper Peninsula and lower Michigan and an important link in the Saint Lawrence Seaway. The Mackinac Straits Bridge, the third longest suspension bridge in the world [3800 feet (1159 meters) long], opened in 1957 and connects Saint Ignace and Mackinaw City. East of the bridge (near top center) are Mackinac Island, a popular tourist and resort area, and larger Bois Blanc Island. North-south-oriented Interstate Highway 75 passes between Mullett Lake to the east and Burt Lake to the west, just north of which is smaller Douglas Lake. This part of northern Michigan is an agricultural area and has commercial fishing, limestone quarrying, and lumbering. The region is a popular year-round resort and recreational area.