Researchers identified environmental factors that explain why reports of Unidentified Anomalous Phenomena (UAP) are more common in certain regions of the country. Most sightings occur in the American West where proximity to public lands, dark skies and military installations afford more opportunities to see strange objects in the air. Understanding the environmental context of these sightings will make it easier to find explanations for their occurrence and help identify truly anomalous objects that may be a legitimate threat.