The helicopter had just taken off from Salinas Airport at 6 a.m. when it crashed in the soundbound lanes of Highway 101.
Witnesses said the area was shrouded in dense fog.
John Sargenti was in the southbound lanes when he came upon the wreckage.
The pilot, 62-year-old Frank Gomes, had just unfastened his seat belt and fell onto the pavement.
"I asked him if he's OK, and he said 'I'm fine,' and he had blood coming out of the side of his face, and his fingers were bleeding, and at that time I noticed that he was kind of going into shock, so I put him in my pick-up until help arrived," Sargenti said.
Gomes is president of Gomes Farm Air Services, which does aerial applications on field crops.
There were no chemicals loaded on the helicopter when it crashed. Gomes was on his way to Watsonville to start a job.
His son Graham arrived at the crash site to learn his father's fate.
"They said he was walking around, so once I heard that, then like, 'all right,'" Graham Gomes said.
This is prime season for aerial spraying. The Salinas Valley's fields are planted with lettuce, strawberries, artichokes and broccoli.
Gomes' company employs 12 people.
Gomes is in the intensive care unit at Salinas Valley Memorial Hospital. Sources said he has a fractured rib and multiple bruises. He may have survived the crash because a tractor-trailer driver managed to swerve out of the way, just in time.
"The big rig driver said this helicopter just fell from the sky in front of him, and he was able to avoid it by about five feet, a very close call," CHP Capt. William Perlstein said.
Investigators from the National Transportation Safety Board said they still need to talk to Gomes to determine what happened. But he's not in a state to be interviewed.