Trenny Gibson was 16 when she disappeared from a Bearden High School horticulture field trip to Great Smoky Mountains National Park on October 8, 1976. The group hiked the roughly 1.8-mile Forney Ridge Trail to Andrews Bald and back; Trenny was last seen about 3:00 p.m. on the return hike, roughly half a mile from the parking area where the buses waited. Classmates said some stopped to rest while Trenny walked ahead and at one point paused to look at something to the right of the trail before she vanished.

An immediate search involved the teacher, students, volunteers, park staff and law enforcement; tracking dogs picked up her scent along different routes, including one toward Forney Creek Trail and another that followed her scent near the Clingmans Dome observation tower for about a mile and a half before ending near a road. Searches continued through October and a renewed effort by her father the following April. The FBI opened an investigation; no public findings or physical evidence — not even a single item of clothing — have ever been found.

Trenny was five feet three inches, 115 pounds, with brown hair, and wore blue jeans, a blue blouse, a blue and white striped sweater, a borrowed brown plaid jacket, blue Adidas shoes and a star sapphire and diamond ring on the day she vanished. Was anyone in the park that afternoon who remembers Trenny or noticed someone approaching the trail where she disappeared?