George Penca, 30, of Hawthorne, California, vanished on June 17, 2011, while hiking with a 20-person church group on the Upper Yosemite Falls Trail. The party reached the top around 2:40 PM and broke up to explore and later meet back in Yosemite Valley, but Penca never rejoined them. He was last seen filling water from Yosemite Creek at the top of the falls.

Penca was not an experienced hiker. When he failed to appear by 9:00 PM the group reported him missing and an extensive search followed. More than 100 search and rescue personnel, helicopters, and dogs searched the steep, difficult terrain for a week. No trace of him or his belongings was found. Theories include becoming lost or injured, wandering off trail, or a fall, but no concrete clues have emerged and the case remains unsolved.

If anyone was on the Upper Yosemite Falls Trail that day or remembers seeing George, please share what you know.