A missing Kansas man spent his final days trapped in the wreckage of his van in a rural Utah ravine and wrote goodbye letters to the family he unexpectedly left in early September.

Utah Highway Patrol trooper Gary Riches says 54-year-old David Welch was found on Oct. 18 by a hitchhiker who spotted the crash in a desolate stretch of eastern Utah more than 50 miles from any town.

They believe Welch, a sales representative for Frito-Lay, fell asleep at the wheel of his minivan on Interstate 70 around Sept. 3, a day after he went missing from his home in Manhattan, Kan.

Riches says Welch was injured in the crash and unable to get out of the van. They believe he survived for days, maybe weeks, keeping a journal and writing notes to his wife and four sons.