Martin was visiting the Great Smoky Mountains National Park with family members on June 14, 1969. Martin was last seen between 2:00 and 4:00 p. m. that day as he played a game of "Hide and Seek" in Spence Field in the park, near the Appalachian Trail. He disappeared behind a bush in the area and has never been seen again. Extensive searches of the area did not locate any evidence as to his whereabouts.