"For instance, a year ago we had the floods so we brought lots of resources from the outside", San Jose Fire Captain Mitch Matlow said. Firefighters increased containment of those fires to nearly 40 percent.
Southeast of Redding, a blaze moved deeper into the Mendocino National Forest, "an area with some hunting cabins and some private property but no towns", Lake County Sheriff Lt. Corey Paulich said.
Following years of drought and a summer of record-breaking heat, huge tracts of forest, shrub and grassland have become tinder that allows even a small spark to explode into a devouring blaze, authorities said.
The major fires in Northern California presented mixed news on Wednesday.
The Carr Fire is one of 17 big fires burning throughout the state. Gov.
The Carr Fire, which broke out July 23 off Highway 299 in the Whiskeytown National Recreation Area, has claimed the lives of six people, including two firefighters.
"Last night, firefighters made good progress on increasing containment on the River and Ranch fires", said Ron Myers, a deputy incident commander with Cal Fire.
Tens of thousands of people remain under evacuation orders.
At a separate news conference on Wednesday, Governor Jerry Brown said the Carr Fire typified a "new normal" authorities are encountering, as large, extremely intense and swiftly spreading wildfires occur more often over a longer fire season. "In this case, we had high tension power line towers that were completely collapsed", said NWS meteorologist Hannah Chandler. "Throughout the day crews will continue to mitigate spot fire potential across control lines", it said.
Officials say 20 people who had been reporting missing in California's devastating wildfires are now accounted for.
The fire burning for 11 days in and around the city of Redding is now 200 square miles (518 square kilometers).
More than 1,000 families have lost their homes, their prized possessions. The weather isn't helping: low humidity, winds, and dry conditions are challenging firefighting efforts.