Carl Herbert Landers, 69, of Orinda, California, vanished on May 25, 1999, while attempting to summit Mount Shasta (14,179 feet). An experienced climber working through a project to climb the highest peaks in every California county, Landers had camped with two fellow Orinda Road Runners, Barry Gillmore and Milton Gaines, at the 50/50 Plateau at about 9,400 feet.

On the morning of May 25 Landers felt unwell and left the camp ahead of his companions, intending to reach Lake Helen, a waypoint on the ascent. He was last seen leaving the campsite and never arrived at Lake Helen; his friends reported him missing when they could not catch up. An extensive search that included over 50 search and rescue personnel, helicopters, and thermal imaging turned up no footprints, personal items, or clues.

The disappearance remains unsolved and his fate unknown, despite years of investigation. Did anyone who climbed Mount Shasta around late May 1999 see Carl or notice anything unusual near the 50/50 Plateau or Lake Helen?