In August 1976, Peter Byrne of the Oregon-based Bigfoot Information Center wrote a letter asking the FBI to “set the record straight, once and for all” on whether the FBI had tested hair samples “which might be that of a Bigfoot.” The answer, it turns out, was no. But Byrne had a mysterious sample, including skin and about 15 hairs, that he wanted tested.

Incredibly, the FBI agreed to do the testing, according to 22 pages of correspondence and news clippings released last week by the agency.