For weeks in the fall of 1967, the cowboys rode from sunrise to sunset in search of the creature no one had ever captured on film. Two rodeo men from Washington’s apple country, they’d traveled to Northern California’s thick forest. They’d read headlines of unidentifiable footprints. The smaller cowboy was driven by a long obsession with the mythic beast known as Bigfoot; the other liked to see things for himself.

One late October afternoon near Bluff Creek, the men trundled on horseback, half a day’s ride from the nearest signs of civilization. The sun shone bright, lighting the leaves all around them in a grand finale of orange and red and yellow. Roger Patterson rode in front, pausing his quarter horse to point his lens toward the leaves, the film chattering inside his rented 16mm Cine Kodak camera. When he finished, he tucked the camera into his saddlebag, leaving the leather flap open.

Bob Gimlin brought up the rear. He rode a quarter horse, leading a pony loaded with supplies behind him.* Patterson navigated around a bend where a large tree had fallen and jammed up the nearby creek—its root system upturned and exposed, like blind fingers reaching for an anchor.