America's fascination with flying saucers began in Washington state on June 24, 1947. Businessman and pilot Kenneth Arnold was flying his small plane from Chehalis to Yakima when he spotted what appeared to be a formation of nine strange aircraft traveling near Mt. Rainier. Arnold calculated they were flying at supersonic speeds of at least 1,200 miles an hour, something military aircraft of the day were incapable of doing.
Arnold described the shiny objects as "something like a pie plate that was cut in half with a sort of a convex triangle in the rear" and that they flew "like a saucer if you skipped it across the water." The term "flying saucer" made it into a newspaper headline and the rest, as they say, is history.
Hundreds of flying disc sightings were reported around the world after Arnold's story hit the newspapers. The most famous event was the alleged UFO crash near Roswell, New Mexico that July.
Were they alien spacecraft or super-secret military planes? The Air Force dismissed Arnold's sighting, saying it was simply a mirage.
Regardless of whether you're a believer, the story of Kenneth Arnold is an amazing piece of Northwest folklore. You can find plenty of details at HistoryLink and Wikipedia.
Oh, and the infamous Men in Black were first encountered that summer in Tacoma following the Maury Island UFO incident.
The truth is out there!