The first vehicles crossed the Mackinac Bridge on this day in 1957. The engineering marvel took 3 years to construct. It weighs over a million tons and has 42,000 miles of wire in its main cables.

The first vehicles crossed the Mackinac Bridge on this day in 1957. The engineering marvel took 3 years to construct. It weighs over a million tons and has 42,000 miles of wire in its main cables.

The first vehicles crossed the Mackinac Bridge on this day in 1957. The engineering marvel took 3 years to construct. It weighs over a million tons and has 42,000 miles of wire in its main cables.

The first vehicles crossed the Mackinac Bridge on this day in 1957. The engineering marvel took 3 years to construct. It weighs over a million tons and has 42,000 miles of wire in its main cables.

The first vehicles crossed the Mackinac Bridge on this day in 1957. The engineering marvel took 3 years to construct. It weighs over a million tons and has 42,000 miles of wire in its main cables.