Though this happened many years ago, the incident left a lasting impression.

I was sitting at my kitchen table around 3:00pm on a summer afternoon (we live in a rural farming area)and I happened to look out the window only to see a very large dark pointed object flying towards my house, from south-westerly direction. The craft flew very slowly just above the trees. As the craft moved across the treeline, it but did not create any air turbulence - neither the trees nor leaves moved. It made no sound and moved very very slowly over my house.
 My daughter and I ran out onto the side gallery and looked up at the object which proceeded over our heads in an easterly direction. Again, it made no sound and I felt no air turbulence. As the nose of the craft moved over the front of the house, we had time to run to the rear side gallery and watch the last 1/3 of the craft pass overhead  (our house is approximately 45 feet wide).
 The width of the craft, I would roughly estimate to be about 200 to 250 feet wide, maybe more. The wing span ran from our road to our barn, which is approximately 2 telephone poles wide(100' between poles). I would estimate it took approximately 7-8 seconds for the last 1/3 of the plane to fly completely by.
 The craft was a huge triangle. The color was a dark greenish black.
It look liked it was made of plastic. I don't remember any lights or windows, but I distinctly recall that the underside of the craft was comprised of  very large tubing (same color as the craft but the pipes looked like large plastic sewer pipes (running back and forth..(south/north) across it's underside.
 I must tell you however, the Plattsburgh Airforce Base was in operation at the time and someone in Howick ( a neighbouring town) also reported an incident and my daughter does not recall the sighting.
Witness indicates that the date of the event is approximate.  PD