Huge silent object witnessed in the sky in Farmington NY in 1979

This was a long time ago so I do not remember the date. I was driving to pick up my step daughter from a girl scout meeting at the Farmington town hall. I was traveling along back country roads to the town hall some 10 miles away. I was on Collette Rd when I noticed the car in front of me pull to the side, get out and stare across the road. I looked to the left and saw a very large silhouette shape directly above a small lumber yard.
I stopped about 100 feet behind the other car and got out as well. It was dark and the craft had no lights on it but with ambient light the silhouette was clearly visible. It was about 50 ft above the lumber yard building. Id guess it was at least 100 yards long and 30 yards high. It clearly was larger then the building and was about 250 ft. from where we stood. I watched it for about 4 to 5 minutes and it slowly started drifting silently at an angle away from us. There were a lot of stars that night and its shape clearly covered stars as it moved. We both got in our cars and drove off. The lead car went straight and I was turning left just about  300 ft ahead. I kept the thing in sight as I drove until I made the turn when I lost sight of it in the dark.
I drove the 7 miles or so to get my step daughter and her friend who were the last kids at the town hall waiting at the front door to be picked up. They both ran up , got in the car excited and told me about the same craft  I had seen , that had passed directly above them.  I then realized it was drifting off in that general direction across farm lands while I ran parallel east bound.
We compared stories as I had seen it from the side and she saw it from below. She described it as two large separate fuselages connected by  a wing type assembly. It made no sound  at all and had no lights. I always wondered if anyone else in the area had seen this that night.
Witness indicates that date of incident is approximate.  PD