A Marshall teen vanished nearly a week ago. 

It's a bizarre missing person case that has two counties searching from the ground, water and now the air.

Nineteen-year-old Brandon Swanson's parents last heard from him Tuesday night. He called them from his cell phone, told them his car was in the ditch and he was walking along a fence line. But his car wasn't where he told them it was, and no one has seen him since.

Lyon County Sheriff Joel Dahl still has more questions than answers. 

"I often ask if we're still searching or if we're in a recovery? And we are still searching," he says. 

Still searching for 19-year-old missing person, Brandon Swanson. 

"We don't believe this is a case where he ran away," Dahl says. 

He didn't likely run away. He seemingly disappeared. The mystery began at 2-am Wednesday morning when Swanson called his parents and told them he drove in the in the ditch near Lynd, just a couple miles south of Marshall. His car was stuck and he needed help. 

"They searched this area, law enforcement searched this area, and once we were able to trace his cell phone calls..."

It turns out the calls were made nowhere close to Lynd. Searchers found Swanson's car in a ditch near Taunton. That's northwest of Marshall off a highway Swanson traveled all the time. 

"He was on the phone with his parents for one time at 45 minutes, explaining to them he was walking," Dahl says.

The best the searchers can do is assume Swanson was walking toward Taunton. So they're searching all nearby streams. 

"We've done ground searches, walkers, atvs, horseback, airplanes, today we have the state helicopter up," Dahl says. 

Still, 6 days later, no trace of Swanson can be found. 

"I wish we could do more. I wish we could give them answers. But I just don't know." 

The 19-year-old man has seemingly vanished.

Sheriff Dahl says he's received second-hand and third-hand information that Brandon Swanson was drinking Tuesday night, which could explain why he was confused about where he was. But Dahl says he can't be sure of that. 

Monday's search from the air did not turn up anything new. 

He was wearing jeans a dress shirt with a black hooded sweatshirt over it. Anyone who may have seen him or has information should call the Lyon County Sheriff.