Clark cites a 1973 encounter as perhaps the earliest suggestion that the U.S. government was involved with ETs. That year, Robert Emenegger and Allan Sandler of Los Angeles, California were in contact with officials at Norton Air Force Base in order to make a documentary film. Emenegger and Sandler report that Air Force Officials (including Paul Shartle) suggested incorporating UFO information in the documentary, including as its centerpiece genuine footage of a 1971 UFO landing at Holloman Air Force Base in New Mexico. Furthermore, says Emenegger, he was given a tour of Holloman AFB and was shown where officials conferred with aliens. This was supposedly not the first time the U.S. had met these aliens, as Emenegger reported that his U.S. military sources had "been monitoring signals from an alien group with which they were unfamiliar, and did their ET guests know anything about them? The ETs said no" Clark The UFO Book, p. 144 The documentary was released in 1974 as UFOs: Past, Present, and Future (narrated by Rod Serling) containing only a few seconds of the Holloman UFO footage, the remainder of the landing depicted with illustrations and re-enactments.
