When I was growing-up in Northern Michigan, they were still paying bounties on predators, like wolves and foxes. I think I was in college the last time I recall someone I knew who had killed a wolf, usually by a trap. In those days, so-called 'long spring' or 'Bridger' traps were still being used:

Generally speaking, as far as Michigan goes, the only known and monitored wolf packs are those found on Isle Royal, and since it's an island, they have a pretty good idea of exactly how many wolves there are at any one time and where they're located (many of them are tagged with GPS devices). Now occasionally one or two will manage to escape over the ice in the winter or even get to the island, generally from Canada, which is actually good, as it tends to freshens the gene pool.
Now the packs in the Upper Peninsula (not including Isle Royal), while there's anecdotal evidence of their existence, they're not as well followed or kept track of. That being said, Isle Royal is technically considered part of the Upper Peninsula.

OCU