Kenneth Arnold’s Mount Rainier UFO June 24 1947

On June 24, 1947, a private pilot named Kenneth Arnold unintentionally kicked off what we now think of as the modern UFO era.

Arnold was a well respected businessman and experienced pilot from Idaho. That afternoon he was flying his single engine plane near Mount Rainier in Washington state. He was not sightseeing. He was searching for a missing Marine Corps transport aircraft and hoping to spot wreckage, since there was a reward involved.

The weather was clear with excellent visibility. Around mid afternoon, while flying at roughly ninety two hundred feet, Arnold noticed a sudden bright flash of light off to his left. He thought it might be sunlight reflecting off another aircraft. When he looked closer, he saw nine strange objects flying in a loose formation near Mount Rainier.

Arnold immediately knew these were not conventional planes. The objects were flat and thin and had a crescent or boomerang like shape. He later said they reminded him of a pie pan cut in half. They appeared metallic and reflected sunlight strongly. What stood out the most was how they moved. They did not fly smoothly. Instead they darted and bounced through the air in a strange, erratic motion.

Arnold watched them for several minutes as they traveled from the direction of Mount Rainier toward Mount Adams. Knowing the distance between the two mountains was about fifty miles, he timed how long the objects took to cross that span using the clock on his aircraft dashboard.

The objects covered the distance in approximately one minute and forty two seconds. That calculation put their speed at over one thousand seven hundred miles per hour. At the time, no known aircraft could even come close to that speed, and the sound barrier had not yet been officially broken.

After landing, Arnold reported what he had seen to airport officials and later spoke with a reporter. During the interview, Arnold explained that the objects moved like saucers skipping across water. He was describing their motion, not their shape. However, the reporter misunderstood and wrote that Arnold had seen flying saucers.

The phrase flying saucers exploded across newspapers nationwide.

Within days, hundreds of people across the United States began reporting similar sightings. The public reaction was immediate and intense. What had once been isolated reports suddenly became a national phenomenon. The U.S. Army Air Forces quietly began paying attention and launched early investigations into the sightings.

Arnold never claimed the objects were alien spacecraft. He consistently stated that he did not know what they were, only that they were not planes, birds, or natural phenomena. He maintained his story for the rest of his life and passed lie detector tests. He gained little from the experience other than unwanted attention and skepticism.

Over the decades, many explanations have been proposed. Some suggested mirages or optical illusions. Others claimed they were secret military aircraft, meteors, or even birds. None of these explanations fully accounted for the reported speed, formation, maneuverability, and reflections observed by Arnold.

Today, Kenneth Arnold’s sighting is widely regarded as the first modern UFO report. It directly led to the wave of sightings that followed, the birth of the term flying saucer, and eventually to official government investigations into unidentified flying objects. Nearly every major UFO case since then traces its cultural roots back to that clear afternoon near Mount Rainier in 1947.

Whether the objects were experimental technology, misidentified phenomena, or something unknown, Kenneth Arnold’s experience remains one of the most important and influential events in UFO history.