SAN FRANCISCO — Six weeks before Gen. Augusto Pinochet overthrew the Chilean government in 1973, Jay Bybee, a 19-year-old Mormon missionary, disembarked in windswept Punta Arenas , nearly 2,000 miles south of Santiago.

“It was a place where you lean on a 45-degree angle to walk around the corner, and then if you don’t change your angle, you fall flat,” then-mission-president Roland Glade remembers. “It was a place you send somebody who knows what they’re doing.”