Leo Hallock, the 79-year-old Casper man who had been missing since Monday, was found dead Saturday on the Wind River Indian Reservation.

Hallock had suffered from epilepsy and a thyroid disorder, as well as forgetfulness associated with Alzheimer's disease, his family said last week. He was believed to have become disoriented after leaving a truck stop last Sunday evening and may have been heading toward family members in the Riverton area with his dog. He missed his monthly thyroid shot and was not carrying his epilepsy medication with him.

Riverton and Wind River police were unable to provide details of Hallock's death Sunday evening, but his son, Jeff Hallock, said it appeared the 79-year-old man had crashed his pickup truck.

"He ran off the road into a little ravine and hit his truck on a boulder," Jeff Hallock said. The elder Hallock also had been stopped by Wyoming Highway Patrol troopers last Sunday for driving in the wrong lane of traffic after becoming confused.

"He must have hit his head or something a little bit," Jeff Hallock said of the accident. "He walked about 400 yards. He found a rock and just laid down and went to sleep."

When Leo Hallock was found Saturday morning, his dog was still watching over him, his son said.

Family members and police have been searching for Hallock since Monday. Casper police posted flyers about the elderly man's disappearance, and family members searched by air for the missing man.

Jeff Hallock said Sunday that he wanted to thank the pilots who had spent their time helping in the search, as well as the many state residents who went out of their way to look for his father.

"I appreciate everybody that took the time and effort and the care to look for my pop," Jeff Hallock said.

"He doesn't have to be sick anymore," he said. "I'm sure my mom was there to meet him when he left."

Staff writer Jenni Dillon can be reached at (307) 266-0619 or Jenni.Dillon@casperstartribune.net.