Bigfoot / Sasquatch

The Patterson-Gimlin Film

On October 20, 1967, Roger Patterson and Bob Gimlin were riding horses along Bluff Creek in northern California when they rounded a bend and encountered a large, hair-covered, bipedal creature at the edge of the creek. Patterson grabbed his 16mm camera and ran toward it, filming approximately 59 seconds of footage before the creature disappeared into the trees. The result is the most scrutinised piece of cryptozoological evidence in history.

The film shows a large, female-featured, hair-covered biped with a pronounced sagittal crest, extremely wide shoulders, and a distinctive pendulous gait unlike any known bipedal primate, including humans. Biomechanics expert Dr. D.W. Grieve of the Royal Free Hospital analysed the gait and found that the stride, cadence, and mechanics were consistent with a very large primate but inconsistent with a human in a suit — a human walking at that stride length would need to walk significantly faster. Dr. Jeff Meldrum of Idaho State University has noted that the muscle and tendon flexion visible in the film would be impossible to replicate in a costume.

Multiple Hollywood special effects companies — including the crew of "Planet of the Apes" — have been challenged to replicate the suit. None have produced a costume that replicates the visible anatomy, muscle movement, and hair dynamics at that scale. In 2002, a man named Bob Heironimus claimed to have worn a suit for the film, but was unable to identify the suit or explain where it went, and his description of the shooting location was inconsistent with the documented site.

Patterson died of Hodgkin's lymphoma in 1972, unable to further elaborate on the footage. Gimlin, still alive as of 2024, has never changed his account. Without a body or additional footage, the film cannot be definitively proven or disproven — which is precisely what makes it the enduring benchmark of the field.

The Skookum Cast

In September 2000, a BFRO expedition to Skookum Meadow in the Gifford Pinchot National Forest in Washington State placed bait — fruit — in a muddy clearing and set up audio and video monitoring equipment. The following morning, the team discovered a large impression in the soft mud near where the bait had been partially consumed.

The impression was unlike a footprint. It showed the lateral side of a large foot including the heel, the outer edge of an apparent calf, the imprint of a forearm, and what appeared to be the impression of a large buttock. The interpretation was that a large primate had sat or crouched at the edge of the mud to reach the bait without committing its full weight to the muddy surface — a behaviour consistent with a cautious large primate.

The cast was taken to the Smithsonian and examined by multiple primatologists, including Dr. Jeff Meldrum of Idaho State University and Dr. Grover Krantz of Washington State University. Both found that the impression was consistent with a large primate but inconsistent with a human in terms of scale, weight distribution, and dermal ridge characteristics in the heel area. The cast was also examined by the Idaho Museum of Natural History, which released a formal statement that the impression could not have been made by a human.

Skeptics have proposed that the impression was made by known animals — a bear, an elk — in a combined sequence. Meldrum has addressed each proposed explanation in published academic writing, finding none of them consistent with the pattern and detail of the full impression. The Skookum Cast remains on display at the BFRO and is considered the most anatomically specific piece of physical Bigfoot evidence ever documented.

The Sierra Sounds

Beginning in 1994, researchers Al Berry and Ron Morehead made a series of recordings in a remote Sierra Nevada wilderness area at elevations above 9,000 feet after receiving consistent reports from hunters of Bigfoot activity. Over several seasons, the two men recorded extensive vocalisations from the surrounding forest during nighttime encounters that they described as terrifying and unlike anything they had heard before.

The recordings — known as the "Sierra Sounds" — were analysed by Professor R. Lynn Kirlin of the University of Wyoming's electrical engineering department and linguist Scott Nelson of the US Navy's Defense Language Institute. Kirlin's acoustic analysis found that the vocalisations contained frequency components, amplitude patterns, and formant structures inconsistent with any known North American animal — including humans performing vocal manipulation or using electronic alteration. The recordings showed apparent vocal tract characteristics of a substantially larger laryngeal anatomy than any known primate in North America.

Nelson's linguistic analysis found what he described as evidence of grammar and syntax within the vocalisations — a structured pattern that suggested linguistic organisation rather than random animal sounds. He published a paper suggesting the recordings captured a form of language, though this interpretation is contested.

The recordings have been widely circulated in the cryptozoological research community and have been submitted to multiple independent audio analysis teams. No team has been able to identify the source as any known animal. Morehead has also published a cast of a footprint from the same location with dermal ridges consistent with other documented Bigfoot trackways. The Sierra Sounds remain the most technically analysed audio evidence in the field.