Project Blue Book Case #11355. On February 12, 1967, multiple witnesses in Grand Rapids, Michigan, reported observing a structured object in the evening sky that did not conform to any recognized aircraft type. The object appeared to have a defined shape — not merely a point of light — and moved in a deliberate, controlled manner across the city.
Michigan had been a hotbed of UFO activity since the spring of 1966, when a series of widely publicized sightings in Dexter and Hillsdale had prompted J. Allen Hynek — Blue Book's scientific consultant — to suggest "swamp gas" as an explanation, generating a national controversy and widespread ridicule of the Air Force's investigative methods. The Michigan sightings directly contributed to Congress authorizing the University of Colorado study (the Condon Committee) that would ultimately recommend closing Blue Book.
Against this backdrop, Grand Rapids witnesses in February 1967 reported an object that appeared to have structural features visible against the night sky — suggesting a solid craft rather than a light source. The object moved silently at an altitude and speed inconsistent with helicopter or fixed-wing aircraft operations. Multiple independent witnesses across the city reported similar observations.
Investigators were acutely aware that Michigan cases received public attention, and the report was investigated with care. No military or civilian aircraft matched the description, and weather data did not support atmospheric explanations. The structured appearance of the object — rare in Blue Book cases — made this sighting particularly intriguing. It was classified "Unknown."