Look man from 11 years ago, I don't want to pee on your parade, but that isn't even close to being true. Cutthroat trout have never been stocked in any of the Great Lakes. Write to MNR if you don't believe me, they will tell you the same thing. No one - not MNR, Pennsylvania, Michigan, Ohio, New York, Wisconsin - no one has ever stocked cutthroat trout in the Great Lakes.
The fish in your pic is just a heavily spotted rainbow trout. Again, ask MNR. Any biologist will tell you that. Spotting, color and overall appearance on rainbows is highly variable. Some fish have lots of big spots, some have fewer fine spots, some have hardly any spots at all. Still all rainbows. You can't identify them by just color pattern or spotting alone.
For what it's worth, the so-called golden trout or palamino trout that Pennsylvania used to stock in the 1990s were also just a color phase of rainbow trout. They were not a different species at all.
Email your photo to MNR and ask them. They will also confirm that cutthroat trout have never been stocked in any of the Great Lakes, by anyone. They don't get "accidentally mixed in with some rainbows" that is not how fish hatcheries work.
Not trying to be a dick, but that is just complete nonsense.