Greens Fork, Ind., April 1958April 1958

In April 1958, a resident of Greens Fork, Indiana contacted the U.S. Air Force about rock fragments he believed were remnants of a meteor strike. Over several letters written between March 1957 and April 1958, the collector described finding scattered particles across the area and shared theories about how a large impact might have broken apart. He noted that some pieces showed signs of heat and blast damage and suggested that pieces of flint in the conglomerate had exploded when heated. He also recalled that a local resident had witnessed something similar falling from the sky about forty years earlier, around 1917.

The Air Force initially expressed interest in the specimen, provided it contained significant metal content. The collector submitted a rock sample to Wright-Patterson Air Force Base for analysis. In May 1958, the Air Force's examination revealed that the specimen was actually a glacial boulder made of basalt, a common igneous rock. The analysis showed it contained iron ore minerals and displayed weathering patterns consistent with transport by Ice Age glaciers, not meteoric impact. Importantly, the specimen bore no signs of aerodynamic heating or surface fusion that true meteorites show when entering Earth's atmosphere. The Air Force concluded the rock was of terrestrial origin, probably carried into the area by glaciers from as far away as Ontario, Canada. No further laboratory examination was warranted.

The Air Force evaluation for this case is listed as unknown. The full case file is reproduced below as held by the National Archives, comprising 13 pages.