Project SIGN Report — Moses Lake Air Force Base, 21 May 1949

This document details a series of events occurring on 21 May 1949, near the Hanford Atomic Plant in Washington, which triggered a military alert under Project SIGN. At 1330 hours, a report was received from the Hanford area regarding a 'Flying Saucer' observed over the East 200 area. The object was described as a round, white or silver disc that remained stationary before accelerating in a southeasterly direction at a speed exceeding that of a jet fighter. Military personnel at the 637th Aircraft Control and Warning Squadron scrambled an F-82 fighter, piloted by a Captain Gardner, to intercept the object. Radar tracking of the object, designated Target 81, was described as spotty and poor, and the target faded shortly after the fighter became airborne. Simultaneously, reports were received of falling bits of paper in the vicinity of the Rattlesnake Mountains. These papers were described as approximately six inches square, colored red on one side and green on the other. A subsequent investigation revealed that these papers were advertisements for an Air Rodeo in Richland. It was determined that the pamphlets were dropped by a PT-19 aircraft, piloted by Don Wise, which was participating in the Air Rodeo. The military concluded that there were two separate and distinct events: the sighting of the unidentified object and the unauthorized dropping of leaflets into a prohibited area. The report emphasizes that there was no connection between the two incidents. The document includes detailed meteorological data and witness information from Max Segoinns, a meteorologist working at the 200 West tower, who estimated the altitude of the object to be between 17,000 and 20,000 feet.