Sometimes called Smoke-phase turkeys.
I first noticed this turkey on our deck (in Wisconsin), and then on across our yard and the neighbor's.

Smokey-gray wild turkeys are rare but not uncommon in Michigan.
This color variation in wild turkeys is a recessive trait,
more common in females than in males, present in Michigan due to
the wild turkey restoration program using birds that were acquired
from Iowa in the 1980s. Some of the birds from Iowa carried this trait.
Through restoration activities, the smokey-gray trait was passed through
the southern Michigan population of wild turkeys. This smokey-gray
color aberration in wild turkeys is not an indicator of birds with
domestic turkey genetics. It is a trait similar to melinism or albinism
and is found in wild turkeys.
...Info from Michigan Department of Natural Resources.