The
drive from Metro airport to Mackinac is at least 4 hours, possibly
more.
There
are airports closer to Mackinac. See list below (I've never used these, before,
and therefore I'm not endorsing one over another). This comes off the Mackinac
Parks travel links website. It looks like Pellston has a Mackinaw
Shuttle.
Pellston Michigan Regional Airport
Northwest Airlink (Pellston)
Great Lakes Air Inc.
Mackinac Island Airport
I
think the most common place to fly in is Pellston.
Good
luck! and enjoy Mackinaw City and Mackinac Island... don't forget to buy some
fudge!
-Anne