The GORP in the film was actually made without peanuts because of a severe peanut allergy among the crew.
Director of photography Shelby Lee Parks has a brief uncredited cameo in the film as "mysterious woman"
Principal photography was only 13 days, with 11 days in the forest. Because of the tight schedule, several scenes were reworked on set because of rainy conditions, which became integral to showing the harsh conditions of the trail.