On the evening of 13 March 1997, two distinct aerial events over Arizona generated thousands of eyewitness reports and became one of the most widely documented mass-UFO-sighting events in American history. The first event — a V-formation of lights moving south from Henderson, Nevada through Phoenix to Tucson between roughly 8:15 and 8:30 p.m. — has been explained as five A-10 Thunderbolts flying in formation. The second event — stationary lights appearing over the Estrella Mountains south of Phoenix around 9:30 p.m. — was later identified by the US Air Force as LUU-2B/B illumination flares dropped by the Maryland Air National Guard's 175th Fighter Squadron during Operation Snowbird at Barry Goldwater Range. Governor Fife Symington III mocked the reports at a press conference but admitted in 2007 that he personally saw the formation.