Thomas Carleton disappeared while on a solo hike in the Adirondacks, New York on October 9, 1993. He left his home early in the morning for a three-day hike in the High Peaks area and planned to stay in lean-tos along the trail without a tent or camp stove.

The last sighting of him was with two hikers who shared a lean-to with him on the Indian Pass Trail, where he told them he was headed up Indian Pass. Carleton, who worked as a psychologist at a state prison in Auburn, lived with his wife and daughter in Skaneateles.

Despite extensive searches, no trace of him has been found and he is presumed to have gotten lost in the wilderness due to the inclement weather on the day of his disappearance. His case remains unsolved.