Flying V formation at an extremely high rate of speed from North to South.At approx. 10:21 MDT on August 13, 2006, three of us observed a V-shaped formation of lights traveling from north to south at a very high rate of speed. The brightness was about the same as 2nd magnitude stars, consisting of 5 to 6 lights in a perfect V shaped formation. One of my fellow observers described it as a giant bird shaped object. The field of view was about 100 degrees across the sky and this distance was covered in 3 to four seconds, again north to south in a straight line. I cannot even estimate the altitude but gut feeling says several hundred thousand feet and several thousands of miles per hour. I am a private pilot and amateur astronomer. We were observing several meteorites on this evening when the event occured. The event was creepy as I've never witnessed such an event before but have heard of them. We are in the process of moving to Riverton, Wyoming where the event occured.