Two points:
How far is it from a road or an old dirt path i.e. can someone drive to it in a truck?
Upper Michigan was under a huge layer of ice not long ago - glaciers can pick up and move large rocks hundreds of miles.. Is this on a terminal moraine? Or is there a steep rock face uphill and above it?
You have to eliminate human dumping first. The out of place thing is easily handled by: glacial processes or humans. Sometimes rocks go for a ride down a steep rock face, too. And keep rolling for a bit.
I cannot tell if it is a conglomerate or construction waste. You decide. Long range rock identification is nearly impossible, sometimes up close is still tough to do, as well. Note: it has not been there terribly long - no lichens. So you can guess what I think. Compare it with the rock in the background.
