Joseph Francis Littwin, 27, disappeared into the Alaskan interior after being last seen on July 13, 1980, near Fairbanks. His final known location was Mile 86 of the Elliot Highway, where he was observed walking toward Sawtooth Mountain. He was reportedly well equipped for an extended backcountry trip.

On that day Littwin wore a brown leather coat and carried a gray backpack containing a sleeping bag, about a week’s worth of food, and a cook stove. He was also armed with a sawed-off 12-gauge shotgun and a .38-caliber revolver. The Alaska State Troopers were notified, but no trace of him has been found and the trail went cold.

What details or local knowledge about Mile 86 or Sawtooth Mountain from that summer might help explain how a prepared outdoorsman could vanish without a trace?