Untitled Sighting

My memory of this is a bit foggy, as I was I believe seven when it happened and am 37 now. At the time my family was living in Cazenovia NY. I would often hike way out in the swamps behind our house with a friend to make forts etc. We would tear the bark off of dead elm trees to make paths for what seemed like very long distances. One day a friend and I were quite a distance out in the swamp chopping away at a rotted fallen tree with hammers when we heard a loud noise. Looking around we saw a very large, dark form that appeared to be a man walking through the swamp very near us. I will never forget the surge of adrenalin and abject fear that I felt. We dropped everything and turned and ran as fast as possible home without looking back. My parents were angry as I had left a hammer there. I refused to go back for quite a while until my older brother accompanied me. I didn't think about this incident too much over the years until later when I have heard people describe bigfoot sightings in terms of 'It looked like a very big man wearing a black raincoat'. This is exactly the description I would give. I don't know, it just seems odd. Why would a man have been alone out in a swamp like that and never said a word to us? Makes you wonder.