A trucker was found dehydrated and incoherent in a roadside ravine in California on Tuesday, leaving officials puzzled as to how and why he ended up stuck there.

The man was found in a ravine along Interstate 8 in East County, California on July 10th near the viewpoint parking spot where the 43-year-old unnamed driver had left his cell phone and wallet inside his still-running semi truck.

According to NBCS San Diego, the driver’s company contacted police when he was late for a delivery, disclosing the GPS location of the truck and allowing officials to begin the search with the help of a Border Patrol tracking dog, the sheriff’s search and rescue unit, and a helicopter.

The helicopter eventually spotted the man at the bottom of a ravine heavy with foliage at around 8:30 a.m.

“If it wasn’t for the (sheriff’s department’s) helicopter, we never would have seen him from the top,” said Sergeant Howard Kluge.

Firefighters then hiked down the embankment and into the ravine, treating the trucker for severe dehydration and heat exhaustion before hoisting him back up to be transported to a hospital. The driver did not show signs of injuries sustained from tumbling down into the ravine and was too dehydrated to communicate with emergency personnel, so how exactly he got down there remains a mystery.

“He was so disoriented… Unfortunately, he was not able to give us much information because of his state,” Kluge said.

He is thought to have been stuck at the bottom of the ravine in the sun for approximately 24 hours.

“There’s nothing here. No water, no restroom,” said one passing trucker who happened to be around for the rescue.

“Maybe he didn’t want to do it out in public. Maybe he wanted to go down and then when he was down there something happened.”

The driver’s current condition, as well as his identity, has not been released but he is expected to make a full recovery.