Byrne asked the FBI to analyze a sample consisting of "15 unidentified hairs and tissue." Byrne wrote he thought the hairs "may be of importance."
The documents reveal a history of Bigfoot-related letters and memos leading up to the FBI Laboratory agreeing to examine the mystery hair.
After a battery of tests and comparisons, the FBI reached a definite conclusion. It was no Bigfoot. The sample came from a creature in the deer family.
This no doubt came as a disappointment to Byrne, who's known for his book The Hunt for Bigfoot.
Byrne remains a notable and controversial figure among Bigfoot aficionados. His persistence with the FBI back in the '70s has gifted us a very entertaining FBI Vault file to enjoy, but we're still waiting on some hard evidence that shows Bigfoot isn't just a fantasy.
Yetis and UFOs and sea monsters, oh my! (pictures)