One of the largest fires, which charred 400 acres west of Yountville Friday, was 60 percent contained Saturday morning, the Napa Valley Register reported. The fire was started Friday morning by problems with a power line.
Officials in many areas, including Sacramento and the Napa Valley, warned that smoke from the fires had created dangerous air conditions for those with respiratory disease.
One of the worst fires was in Yolo County, where several homes were destroyed. The blaze swept across thousands of acres.
Dr. John Madigan, a UC Davis veterinarian, told the Sacramento Bee that he and his colleagues euthanized 50 sheep Friday after finding 15 that were already dead. They said they expected to return Saturday to look for more injured animals.
Daniel Berlant, a spokesman for the California Department of Forestry and Fire Protection, said a wet spring had created luxuriant grass, making the normal late-summer early-fall fire season in California even more dangerous than usual.