Fire officials said late Tuesday that crews had gained ground against a devastating Northern California blaze that has killed at least one person and destroyed hundreds of homes and businesses. 

As of 7:15 p.m. local time, Cal Fire said the so-called Valley Fire in Lake County north of San Francisco was 30 percent contained. The fire, which started Saturday and was fueled by drought-stricken vegetation, has burned 105 square miles and destroyed 585 homes. Another 9,000 structures remain threatened.

Earlier Tuesday, fire investigators working to determine the cause of the inferno said they had narrowed their focus to an area in the small community of Cobb. Cal Fire spokesman Daniel Berlant told the Associated Press that investigators were examining the area where the fire was first spotted. The exact cause of the conflagration remains under investigation. 

The Lake County fire and another blaze about 120 miles to the southeast have displaced 23,000 people and were the worst of a dozen wildfires burning in the state. The Lake County fire spread into northern Napa County, but the region's famous wine valley was not threatened.

Scores of people in Lake County were escorted back to their homes Tuesday to check on pets and farm animals. They were allowed to remain for 15 minutes to feed and give water to the animals.

In the community of Middletown, some residents cried as they walked through the rubble of their homes while others shared stories of survival. Gary Herrin sobbed as he walked through what had been his childhood home.

"Yep, grew up here, was able to walk to school from here. Many friends lived close by," Herrin recalled, looking around. "There's a lot of good people here, but it's a ghost town now, it's really eerie."

His brother had been living in the home and members of his extended family resided nearby.

"I go to my brother-in-law's house, my niece's house, and there's nothing, nothing, ashes," Herrin said.

During his return, Herrin walked to the charred remains of an old Chevy pickup and gave it an angry kick. The truck was the only possession of his late father that he still had. Other people found nothing but concrete foundations and chimney stacks.

"You've got to look at everybody's, everybody's loss," Herrin said. "It's never going to be about one person. It's about everybody."

Rancher Lisa Comstock said she and her three dogs survived the raging fire in rural Middletown by jumping into a water trough as flames neared her home.

Comstock was also able to keep her horses nearby as the fire burned around them.

"The flames were coming over that mountain and surrounding this place like there was no tomorrow," she said. "I jumped in the water trough with all the dogs, and the horses came up around. Thank God they just stayed here."

At one point she was sure she wasn't going to make it but talking to her animals helped keep her and the animals calm.

"If this is how I go, I'm not leaving these animals. That's all I could think of," she said.

Thousands of utility crew members and firefighters were working diligently to control the blaze and get life back to normal for as many people as possible, said California Department of Forestry and Fire Protection spokesman Dave Shaw.

"We're working as hard as possible to try to put out the hotspots in these burned areas so that when people do come back there won't be a risk of them getting burned themselves," he said.

The utility companies were trying to restore power to the area and water was flowing in some areas of town.

One person has been confirmed dead, and others were unaccounted for, but authorities said they could be staying with relatives, on vacation or elsewhere and not impacted by the fire.

The dead woman has been identified as Barbara McWilliams, 72. She told her caretaker she didn't want to leave her home near Middletown. The world traveler and sharp-minded woman with advanced multiple sclerosis said she would be fine.

Her body was found Sunday in her burned-out home after flames kept Lake County sheriff's officials from reaching her.

Lake County has been particularly hard-hit by wildfires this summer. In late July, a wildfire east of Clear Lake destroyed 43 homes as it spread across more than 100 square miles. Another fire erupted Aug. 9 several miles from the community of Lower Lake.

The Associated Press contributed to this report.