15 Most Famous UFO Incidents in American History

Curiosity about unidentified flying objects has been part of American life for generations, and a handful of cases stand out for their detailed witness accounts, official investigations, and cultural impact. From radar-confirmed events to photographs and alleged close encounters, these incidents span small towns, major cities, military bases, and busy airports. Many prompted inquiries from the U.S. Air Force’s Project Sign, Project Grudge, and Project Blue Book, as well as local and federal law-enforcement agencies. Here are 15 of the most talked-about UFO incidents in American history, presented with key facts on what happened, who reported it, and what investigators concluded (or couldn’t).

Kenneth Arnold Sighting

On June 24, 1947, private pilot Kenneth Arnold reported seeing nine fast-moving objects near Mount Rainier, Washington, estimating their speed at over 1,200 mph. He described their motion as skipping “like a saucer,” a phrase that helped popularize the term “flying saucer.” The sighting drew national media coverage and triggered an early wave of post-war UFO reports. The Air Force looked into the case, offering explanations ranging from mirages to aircraft formations, but issued no definitive conclusion.

Roswell Incident

In early July 1947, debris recovered from a ranch north of Roswell, New Mexico, was first announced by the local Army Air Field as a “flying disc” and later recharacterized as a weather balloon. Decades later, declassified materials linked the recovery to Project Mogul, a high-altitude balloon program designed to detect Soviet nuclear tests. Eyewitness claims and additional testimony surfaced over time, leading to competing interpretations of what was found. The U.S. Air Force issued reports in the 1990s attributing accounts of bodies to later-era anthropomorphic test dummies and training recoveries.

Maury Island Incident

In June 1947, Harold Dahl and Fred Crisman claimed that slag-like debris fell from a hovering object over Puget Sound near Maury Island, Washington. Investigators, including early Air Force intelligence personnel, examined fragments later identified by some analysts as industrial by-products. The case became entangled with conflicting witness statements and allegations of a hoax. While influential in early UFO lore, official assessments did not substantiate an anomalous craft.

McMinnville UFO Photographs

On May 11, 1950, Paul and Evelyn Trent of McMinnville, Oregon, captured two photographs of a disc-shaped object over their farm. The images were published widely and later analyzed by multiple researchers, with debates focusing on lighting, scale, and potential suspension lines. Despite extensive scrutiny, no consensus was reached on a mundane explanation. The photos remain among the most famous visual records in American UFO history.

Lubbock Lights

In late August 1951, multiple witnesses in Lubbock, Texas—including college professors—reported formations of bright, fast-moving lights crossing the night sky. Photographs were taken by a local student, adding detail to the accounts. Project Blue Book investigated, exploring explanations such as birds reflecting city lights and temperature inversions, but could not conclusively resolve all reports. The event is notable for independent, near-simultaneous sightings across the area.

Washington, D.C. UFO Incident

Across two weekends in July 1952, radar operators at Washington National Airport and Andrews Air Force Base tracked unidentified targets while pilots and ground observers reported lights maneuvering over restricted airspace. Interceptor jets were scrambled, but the targets frequently vanished and reappeared. The Air Force attributed the radar returns in part to temperature inversions, a conclusion challenged by some controllers and pilots. The incident prompted a high-level press conference and policy discussions on handling future reports.

Kelly–Hopkinsville Encounter

On August 21–22, 1955, residents near Hopkinsville, Kentucky, reported small, luminous entities approaching a farmhouse, resulting in an hours-long standoff and multiple police responses. Officers documented bullet holes and witness statements but found no bodies or conclusive physical evidence. Some researchers later suggested misidentified great horned owls combined with heightened stress and lighting conditions. The case is frequently cited for the number of witnesses and the detailed descriptions of the entities’ movements.

Levelland UFO Case

On November 2–3, 1957, motorists around Levelland, Texas, reported bright objects approaching their vehicles, allegedly causing engines and headlights to fail. Law-enforcement officers collected multiple, independent accounts over several hours across different locations. Project Blue Book considered electrical storms and ball lightning among potential explanations, though not all reports aligned neatly with those hypotheses. The incident is often referenced for the recurring vehicle-interference claims.

Lonnie Zamora (Socorro) Incident

On April 24, 1964, Socorro, New Mexico, police officer Lonnie Zamora reported a loud roar, saw an egg-shaped object on landing legs, and observed two small figures before the craft departed. Investigators documented ground impressions and scorched vegetation at the site. The case drew significant attention because Zamora was considered a credible witness and because of the physical traces. Project Blue Book listed it as “unidentified” after examining hoax and test-vehicle possibilities.

Exeter Incident

In the early hours of September 3, 1965, near Exeter, New Hampshire, police officers and a civilian reported a large, bright object moving silently and at low altitude. Multiple patrolmen filed statements describing red lights that maneuvered in ways they found unusual. The Air Force suggested aircraft and atmospheric effects, but the officers maintained their accounts. The case became a touchstone for law-enforcement UFO reports in the 1960s.

Kecksburg UFO Incident

On December 9, 1965, witnesses in Pennsylvania observed a fiery object crossing the sky, followed by reports of a metallic, acorn-shaped object in woods near Kecksburg. Local authorities and military personnel responded, and some residents claimed a rapid removal operation took place. Official explanations pointed to a meteor and reentering space debris, while researchers examined trajectories and archival records for corroboration. The precise nature of what, if anything, was recovered remains disputed in public sources.

Malmstrom AFB Missile Incident

In March 1967, personnel at Malmstrom Air Force Base in Montana reported that multiple Minuteman ICBMs in an underground complex went offline during a period that coincided with accounts of unusual aerial activity. Technical teams restored the missiles to alert status, and subsequent discussions focused on whether the malfunctions had a conventional cause. Declassified materials confirm the missile outages; links to any unidentified aerial phenomena remain unproven. The event is frequently cited due to its national-security context.

Travis Walton Abduction

On November 5, 1975, logger Travis Walton disappeared near Snowflake, Arizona, after co-workers reported a brilliant object in a forest clearing; he reappeared five days later with a detailed account of an abduction experience. Law-enforcement officers interviewed the crew, and multiple participants took polygraph examinations with mixed results over time. The case generated books and later dramatizations while continuing to draw competing analyses from investigators. Official agencies did not issue a definitive explanation beyond recording the missing-person and recovery timeline.

Phoenix Lights

On March 13, 1997, thousands of witnesses across Arizona reported a massive V-shaped formation of lights and, later that evening, stationary lights over the Sierra Estrella range. The U.S. military attributed the stationary lights to flares dropped during training, documented in flight records and range logs. Researchers distinguished between the earlier formation, seen moving across the state, and the later flare sequence. The event is one of the most widely reported mass sightings in the United States.

O’Hare Airport UFO Sighting

On November 7, 2006, United Airlines employees and pilots at Chicago O’Hare International Airport reported a disc-shaped object hovering over a terminal before ascending rapidly and leaving a hole-like opening in the cloud layer. The FAA received inquiries and cited a lack of radar confirmation while classifying the event as a weather phenomenon. Multiple written reports from airline personnel described consistent details of the object’s size and movement. The case is notable for occurring in tightly controlled airspace with numerous trained observers.

Share your take on which cases deserve more scrutiny—and why—in the comments below!