Hessdalen is a small valley in the central part of Norway. At the end of 1981 through 1984, residents of the Valley became concerned and alarmed about strange, unexplained lights. Project Hessdalen was established in the summer of 1983 to study Unidentified Aerial Phenomenon (UAP) and Unidentified Flying Object(UFO) sightings. A field investigation was carried out between 21 January and 26 February 1984. Fifty-three light observations were made during the field investigation.