Mackinac Bridge goes over what lake?

The macinac (pronounced "mack in aw" not "mack in ak") is a suspension bridge.

Opened November 1, 1957 it has a total length of 3,800 ft (1,115m).

It is the third longest suspension bridge in the US (only the Golden Gate & Verazzano-Narrows are longer) and twelfth longest in the world.