Bluff Creek / Patterson–Gimlin Film — 1967

The encounter

On October 20, 1967, Roger Patterson and Bob Gimlin reported encountering a large upright hair-covered figure at Bluff Creek in northern California while traveling on horseback. Patterson filmed the retreating subject on 16mm color film, creating the artifact now known as the Patterson–Gimlin film.

The film's existence is not disputed; the identity of the filmed subject remains unresolved. Patterson and Gimlin gave early accounts of the event, including a radio interview recorded six days later. Later decades produced extensive technical analysis, skeptical criticism, claims of a human performer and costume, and continuing debate over scale, gait, anatomy and film provenance.

The case is therefore best understood as several evidence layers rather than one binary authenticity question: the surviving film, the witnesses' testimony, contemporary reporting, later technical analyses, and later hoax claims each have their own provenance and limitations. None of those layers alone establishes what the subject was.