Thomas Mylon Tom Gronewold was 19 when he was last seen in the Libby, Montana area on August 7, 1966. He had spent that summer working a Forest Service job in Troy and was floating on inner tubes on the Kootenai River between Troy and Libby with two friends when they encountered rough water. Tom was flipped from his tube and reportedly surfaced twice before disappearing; searches in the area failed to locate him.

Tom is described as a young White man with blond or strawberry-colored hair and blue eyes. His listed height range is 5 feet 1 inch to 5 feet 10 inches and weight 185 to 198 pounds. A distinctive feature noted was that the ends of the little finger and ring finger on his left hand were shorter from a farm accident; he may have been wearing swim trunks or denim cutoffs when he vanished.

Tom had graduated Carthage High School in 1965, attended Northeast Missouri State College for a year, and worked the Forest Service summer job that brought him to the Kootenai River area. His case remains listed with NamUs (MP82175) and with Montana missing-person resources so identifying information stays available. Does anyone who was in the Troy or Libby area that August remember the river conditions or the day Tom disappeared?