Recalling his Boy Scout training, he decided to follow a small stream toward what he hoped would be a camp or town. At night, he curled up between tree roots and covered himself with moss. He ate wild berries. On the second day, tripping as he walked in the stream, he lost his sneakers, which he had tied together and carried over his shoulder.

Not long after, trying to throw his soaked jeans onto a rock in the stream, he misjudged and watched as the water carried them away. “I couldn’t believe it,” he recalled in his book. “My pants were gone. There I was like a Kewpie or something.”

Small stones cut his feet. Near-freezing temperatures at night stiffened his limbs. Mosquitoes, black flies and moose flies bit.

“Somebody ought to do something about those black flies,” Mr. Fendler said in “Lost on a Mountain in Maine.” “They’re terrible — around your forehead, under your hair, in your eyebrows and in the corners of your eyes and in the corners of your mouth, and they get up your nose like dust and make you sneeze, and you keep digging them out of your ears.”

He prayed. He hallucinated. One day, he heard a plane circling overhead but could not find a clearing to wave at it. Twice he encountered bears, foraging, as he was, for berries. He began to lose strength and hope, before the sight of telephone wires suggested to him that he was on the right track.

On July 25, he came to a clearing and saw, across a lake, two canoes and a small cabin, part of a remote camp on the east branch of the Penobscot River run by Nelson McMoarn. Mr. McMoarn emerged from the cabin and did a double take.