David William Barth was 70 when he was last seen on July 30, 2004, at his home in Emigrant Gap, California. His wife noticed him missing from the porch about ten minutes after he had been sitting there. A neighbor reported seeing him walking eastbound along the railroad tracks near Blue Canyon carrying a rust-colored backpack and possibly heading out for a hike.

Barth had dementia and walked with a pronounced limp from a prior leg injury; he also had other health problems that raised serious concern about his ability to survive unaided in the rugged terrain around Emigrant Gap. Local law enforcement and searchers conducted extensive searches but never located him, and his disappearance remains unsolved.

If anyone remembers seeing David near the railroad tracks, on a hike that day, or has information that could help, please share what you know with the authorities.