A father and three children who vanished on a Christmas tree-cutting trip in the Northern California mountains were found alive Wednesday after huddling in a culvert for warmth during three days of heavy snow.

"Our hearts are all full right now," said Cory Stahl, who closed his pest control business so his employees could help look for the father, Frederick Dominguez, their co-worker. "It's a very merry Christmas now."

A California Highway Patrol helicopter crew spotted Dominguez atop a small bridge and landed nearby, sinking into 2 feet of snow, flight officer David White said. The family had taken shelter in a culvert beneath the bridge and stomped "help" in the snow, White said.

White said it was the last opportunity for the helicopter, with snow falling heavily as it descended.

"With another storm coming in, they were just happy to get out of there and get home," he said.

The helicopter ferried the family to safety in two trips, the two youngest children brought out of the woods first.

Daughter Alexis, 14, and Joshua, 12, stepped from a rescue helicopter and were immediately enveloped in a cluster of well-wishers carrying heavy blankets while the chopper went to fetch their father and brother.

Dominguez smiled at cheering family and friends as he and 18-year-old Christopher emerged from the helicopter a short time later.

All four were walking, talking and drinking hot chocolate while being checked at Feather River Hospital for dehydration, hypothermia and frostbite, treating physician Kurt Bower said. He expected them to be released later in the day.

Bower said the family had some water but nothing to eat during their ordeal.

"I'm surprised how good they are," he said. "There's a miracle from God in there somewhere."

More than a foot of snow had fallen in the area since the family disappeared, covering any tracks leading from the truck. Drifts ranged from 1 to 7 feet deep across the heavily wooded and canyon-crossed area.

The rescue teams had been racing time and the elements to find the four, as a powerful storm carrying even more snow was headed into the region. The search effort expanded with a break in the weather Wednesday morning, and the helicopter was able to join the search around midday after low-lying clouds lifted.

Frederick Dominguez, 38, and his children have been missing since Sunday in the region about 100 miles north of Sacramento. Dominguez's pickup truck was found Monday night parked along a mountain road some 25 miles northeast of Chico.

The family also appeared better equipped than rescuers initially thought. Earlier reports said the family went into the woods wearing T-shirts and light jackets, but all four were wearing heavy winter coats when they emerged from the helicopters, and some had wool caps.

"We're all extremely thankful and feel like we got a Christmas miracle," said Teresa Kennebeck, a secretary at Paradise High School, where Alexis is on the cheerleading squad and the soccer team.

Dominguez's co-workers said he is devoted to his children and takes them to church every Sunday, as he did this weekend before heading out in search of a Christmas tree.

"He lives for his family," said Mairleen Grove, the pest company's office manager. "When he walks in the door, he makes everybody smile."

Dominguez parked his Chevrolet pickup along a road near the mountain hamlet of Inskip on Sunday afternoon, then likely walked downhill into the woods with his children and became lost, Butte County Search and Rescue spokeswoman Madde Watt said.

"You could get turned around very quickly," she said.

It was clear at the time and for hours after the family entered the woods. The first storm wave didn't hit until Monday.

Because Dominguez had custody of his children at the time, his ex-wife did not know they were missing until she discovered that her youngest child failed to show up at school Monday. Authorities were alerted at 8 p.m. Monday and immediately began a search.

They quickly found the pickup — a bare spot beneath it, indicating little snow when the trek began — but at least 8 inches of snow was covering the ground, hurting efforts to track them.

The search effort expanded significantly Wednesday morning, as snow had stopped falling for the first time since the family went missing.

It intensified as another moisture-laden Pacific storm was heading toward California, expected to blanket most of the northern state with rain and snow by late Wednesday afternoon.

About 2 feet of snow was expected to fall Wednesday night and Thursday morning in the area where the family had been missing, said Jared Leighton, a meteorologist with the National Weather Service office in Sacramento.