Untitled Sighting

I was in Wexford county between Cadillac and Manton in the long lake state forest with a few friends.  We were back in the woods a way by a creek.  Just talking and scouting for deer season.  I was throwing stones into the ceder swamp on the other side of the stream when we heard a low growl sound.  The next think i saw was a shadow moving though the edge of the swamp.  Not a clear visual but i know it was standing up right and walking.  Then rocks started flying back up in our direction.  We found it amusing so we threw a few more back into the swamp.  Then we heard the growl again and branches start breaking.  We turned and ran as fast as we could back to the Jeep and got out of there.