Project 10073 Record Card — St. Croix Falls, Wisconsin, 10 October 1951

This document details a sighting of an unidentified aerial object on 10 October 1951, near St. Croix Falls, Wisconsin. The primary witnesses were J.J. Kaliszewski and Jack Donachue, who were in an aircraft conducting a trajectory flight for a high-altitude balloon project managed by General Mills. At approximately 10:10 AM, the witnesses observed an object moving from east to west at an altitude significantly higher than their balloon, which was at 20,000 feet. The object was described as having a peculiar glow and being approximately one-quarter the size of the balloon. Its flight behavior was noted as highly unusual: it performed a rapid slight dive, levelled off, turned sharply to the left, and then climbed at a 50 to 60-degree angle with what the witnesses described as 'terrific acceleration.' The sighting lasted approximately two minutes. The witnesses explicitly stated that the object was not a balloon, jet, conventional aircraft, or celestial star. The sighting was corroborated by ground observers Doug Smith and Richard Dorian, who were tracking the balloon flight using a theodolite at the General Mills tracking station. The document includes internal correspondence and intelligence reports, including a request for evaluation by the 133rd Fighter Interceptor Wing. The reporting intelligence officer, a Major in the USAF, noted that given the technical background of the observers and the fact that four men confirmed the sighting, the report is considered highly reliable. The document also references a previous incident, Project Saucer Case No. 122, involving C.B. Moore, an aeronautical engineer at General Mills, who had previously tracked an unknown aerial object in 1949. The materials reflect the Air Force's interest in these sightings as part of Project 10073, despite the lack of a definitive official explanation for the object's nature.