GALLERY: Notable Colorado UFO sightings uncovered in Project Blue Book
After the infamous alleged alien landing in Roswell, New Mexico, in July 1947, the US Air Force investigated 12,618 sightings from 1947 to 1969, and many of those cases occurred in Colorado.
The objects were observed passing over a B-52 at a high rate of speed. One of the witnesses remarked, “Are those airplanes? Boy! They are sure fast!”