Britain releases government UFO files 1978-87

http://news.bbc.co.uk/2/hi/uk_news/7398108.stm

Both the craft I saw above Mt. Shasta City around 1990 and the print of a UFO in the snow in 1974 were very similar to the shapes that are drawn in this article from bbc.com

The biggest difference was that in my 1990 sighting over the city of Mt. shasta in Northern California, the ufo was accompanied by three double bladed helicopters of the type used in Viet Nam used to carry up to 40 or more soldiers. In this case they were unmarked. I had been washing dishes by hand during the morning in my house and heard a terrible racket caused by 3 of these double bladed helicopters blades breaking the sound barrier at their tips as they moved forward. However, when I went outside and looked up they were accompanying a UFO that looked just like the impression on the snow at about 25 to 30 feet in diameter that I had seen in 1974. They were about 2000 feet up so I could see them very clearly. Since the town is at 3500 feet elevation that meant they were at about 5500 feet elevation approximately. The saucer held still in the air with no visible movement while the helicopters(with no military markings only painted dark grey) hovered in formation in a stationary position. Within 30 seconds to a minute the flying saucer vanished and I was completely amazed because this had happened in broad daylight on a clear day with no clouds in the sky and no real wind. The three helicopters held their formation and moved in formation then up toward hiway 89 and toward northeastern California and Nevada.

Note: After thinking about all this for about 2 years I came to the conclusion that either the helicopters were generating a hologram that looked real or I had witnessed time travel by UFO because of the way everything had happened.