DES MOINES, Iowa (AP) — David Schultz’s semi-truck was found two weeks ago on a rural highway in northwest Iowa, its trailer still filled with baby pigs he was transporting. Schultz’s wallet and phone were inside, and his jacket was on the side of the road.

But Schultz was nowhere to be found, and his Nov. 21 disappearance outside Sac City remains a mystery.

His wife said something must have gone wrong, calling the 53-year-old father of two a dependable man with a strong work ethic.

“This is not something David would do,” Sarah Schultz told the Sioux City Journal. “He would never leave. His family is his life.”

Hundreds of people have volunteered to search for Schultz, but after scouring 100,000 acres near the highway, the effort was paused as searchers considered their next steps. Leaders of the search were convinced they would have found Schultz if he had wandered off because of a medical emergency or some other problem.

Iowa’s Division of Criminal Investigation is assisting the Sac County Sheriff’s Office and the Lake View Police Department in the case. Iowa DCI referred The Associated Press to the Sac County Sheriff’s Office, which declined to comment on the active investigation.

Schultz, of Wall Lake, didn’t arrive as expected with the load of pigs on Nov. 21 in Sac City, Iowa, a small farming town about 90 miles (145 km) northwest of Des Moines. No one could get him on the phone.

The truck was found later that afternoon, less than 10 miles northeast of his destination, a livestock dealer in Sac City, according to Jake Rowley, the regional team leader of United Cajun Navy, a nonprofit search-and-rescue organization which typically responds to natural disasters.

Schultz’s truck wasn’t running when it was found in the middle of the two-lane highway. It was facing northbound, Rowley said, even though it should have been headed southbound to get to Sac City.

The disappearance has mystified surrounding communities in Iowa, prompting more than 250 individual volunteers to join in the search.

United Cajun Navy had volunteered to take over the search to allow law enforcement to focus on the investigation, Rowley said, but he hopes to see more from Iowa DCI and other investigators.

“Maybe they’re doing a bunch on the computers, but they’re just not really active in the scenario,” Rowley said. “An organization the size of DCI should be able to come in and make a splash, in my opinion.”