The Mackinac Area is the northernmost part of Northern Michigan, just south of the Straits of Mackinac and the Mackinac Bridge to St. Ignace in the Upper Peninsula.
The region has a bit of a problem with consistency in spelling and pronunciation. The Straits, Bridge, and Island are all spelled "Mackinac" but pronounced "Mackinaw"; with the final "c" left silent. The Village of Mackinaw City and the Coast Guard cutter named after it are pronounced the same way, but are also spelled that way. (The "Mich" is pronounced "Mish", just like in the name of the state; at least that's consistent.)
The regional names are consistent, considering the local Indians (various tribes) had their way of pronouncing and area, and the French and English had their way of spelling what they heard from the Indian pronunciations. Michigan remains very historic in this sense. It has kept the spellings and pronunciations as were originally given by Indian, French and English.