Well from 2004 till this August, i lived in southern saginaw county, right near the shiawassee game preserve and michigan trophy hunts game ranch.
last year in 2009, trophy hunts got closed down, i wont comment on why or the scuttle bug about what really went on there but, they had a whole mess of pigs, russians, domestics and crosses. the DNR removed alot of them, but a large number of them got out thru the fence and onto a large nearby farm. i talked with the farm owner, and made many a trip out looking for them hogs. 1 hog was shot by a son of a guy in the hunt party.
alot of hunters claim to seeing hogs on the tracts of state land around the farm fields, but next to nothing has been confirmed by the dnr.
i am out there as much anyone else, and i have not seen a single hog track, never mind a hog itself, which i do find curious.
this summer, the dnr checking on some rumors did find a good sized black bear with a cub in the shiawassee flats area, but no hogs ...
regardless of what the pig experts say i think the winter kills a good number of them off, and i just think there is just not that many of them state wide.