Untitled Sighting

I live in Tazewell VA. Last Friday on June 20, 2014 me and my son was cutting hay on my dad's farm in Thompson Valley near Route 16. It was close to 3pm and the sun was mostly out. I was cutting hay way ahead of my son, the field is half surrounded by woods and near the Clinch Mountains. I had made a pass by the corner of the field on a hill side and my mowing cutter is heavy so it slid down the hill while cutting, and left a strip of grass about 60 foot long before I seen it. So I raised the cutter and turned my head to back up and re-cut and out of the corner of my eye something caught my attention. I turned my head a little more and I saw something real dark or black and tall and slim with long legs running on an angle away and down the hill real fast . Now the beast was not on our side of the property and the slim patch of woods where I seen it was only about 4 ft. wide. The sun was bright so I saw it for the 3 to 5 seconds real fine! Below where it ran and beside one the upper ends of the property are thicker woods! At first it did not dawn on me what I just had seen because we were trying to get the hay cut before it got too late. But as I was going on and thought about why was a man there and ran off when I stopped the tractor to back up! Then it dawned on me it was to tall and it was blackish in color, and the 3 steps I plainly saw it make was the distance between 3 fence post. We put our fence post around 10 feet apart so that would make it about 25 to 30 feet in length in 3 STEPS! I then knew what I saw was human shape but too big for a human and if it was someone I would have saw colors for the pant and shirt, there was no colors just dark. I forgot to mention the bigfoot I saw was around 100 yards away so the first time I passed it not seeing it, and when I stopped to back up with the tractor It must have thought I saw it and that's when it ran off I guess? I stopped to tell my 17 year-old son what I saw, he is 6ft 2 and slender. He crossed the fence where I saw it and stood there till I walked to the place I had seen it and I knew it was much taller than him! We found no hair or foot prints just cow and horse. And one horse hair. I am a christian man.  would not lie and tell this occurrence of my life if it was not so. That image is burnt in my mind till the day I die! I would have to say it was around 7 foot tall! And fast!