A Sierra Nevada fire claimed an additional 250 homes, bringing the total to 503, California fire officials said Saturday after making new assessments.
California Department of Forestry and Fire Protection spokesman Mike Mohler said the increased count comes as firefighters make progress and damage inspection teams have access to affected areas.
Cal Fire had reported 252 homes destroyed as of Friday night by the fire burning in Amador and Calaveras counties. Two deaths have been reported.
The fire is 65 percent contained.
A separate blaze in Lake County, about 170 miles northwest, has killed three people, destroyed nearly 600 homes and burned hundreds of other structures.
Heat was descending again on the two deadly and destructive Northern California wildfires after a few days of fair and favorable conditions, and it brought with it fears the blazes could come back to life and major gains could be undone.
"We're looking at predicted weather of 100 degrees for the next couple of days, and at least mid-90s throughout the weekend," Scott Mclean, a battalion chief with the California Department of Forestry and Fire Protection, said Friday.
That makes it essential that the smoldering remains of the two giant blazes be dealt with as quickly and thoroughly as possible, Mclean said.
"You've got some high temps, high winds that could stir up those ash piles and those ember piles," he said. "We have to do that mop-up to be sure this fire goes to bed."
By Saturday morning the blaze in Lake County had charred 116 square miles and was 48 percent contained.
The two killed by the Amador and Calaveras county fire — 66-year-old Mark McCloud and 82-year-old Owen Goldsmith — died after rejecting orders from authorities to evacuate, Cal Fire spokeswoman Lynnette Round said.
It wasn't clear if the three dead in Lake County had received evacuation notices, but two of them declined requests by friends and family to leave.
The body of 72-year-old Barbara McWilliams, who used a walker, was found in her home in Anderson Springs. Her caregiver, Jennifer Hittson, said there were no evacuation orders when she left McWilliams' home on the afternoon of Sept. 12, and no indication the fire was that serious.
She asked McWilliams if she wanted to leave, but the retired teacher declined, saying the fire didn't seem bad.
Elsewhere in Anderson Springs, the body of former newspaper reporter Leonard Neft, 69, was found near his burnt car after what may have been an attempt to escape, his daughter Joslyn Neft said Friday. His wife had asked him to leave earlier Saturday, but he said the fire looked far away.
The body of Bruce Beven Burns, 65, was found in a building on the grounds of his brother's recycling business, where Burns also lived. It's unknown why he stayed.
A number of survivors of the fire said they never got an official evacuation notice when the danger was at its peak a week ago.
High school math teacher Bill Davis watched from his home as smoke mounted. From a previous fire in late July, he knew to expect a recorded call on his cellphone or look for someone coming through the neighborhood with a bullhorn yelling for people to evacuate.
"None of that happened," he said. His house in Lake County burned after he finally rounded up his cats and left.
Authorities defended their warnings and rescue attempts, saying they did all they could to reach people in the remote area of homes, many prized for their privacy.
"You may get that notice, or you may not, depending on how fast that fire is moving," Round said. If you can see the fire, you need to be going."