In 1976, Gary Frank Sotherden’s appetite for adventure and the outdoors led him to the Arctic Circle, where he and a friend planned to walk on opposite sides of the Porcupine River in northeastern Alaska, reuniting when the cold set in and the river froze, his brother said.
The friend made it out, but Mr. Sotherden was never heard from again.
Planes flew above the remote, winding river in search of Mr. Sotherden, who was from Clay, N.Y., which is about a dozen miles northwest of Syracuse. The police and mountain guides also searched on land, but their efforts were unsuccessful.
What happened to Mr. Sotherden was a mystery that endured for nearly 50 years — until Thursday.
