During the Cold War, the U.S. Air Force maintained a radar base on Vermontís 3,438' East Mountain.
Named the North Concord Air Force Station, this remote facility started operating in 1956. At the height of its operations, about 175 men worked at the station; they lived in a little Quonset hut village, complete with store, bowling alley, and theater, about a mile down the mountain.
In 1961, according to military reports, a strange object appeared in the skies above East Mountain and remained visible for about 18 minutes. Given that the events involving Barney and Betty Hill happened just a short time later, some assert that this was the same UFO. The base closed in 1963 and now sits abandoned.