Firefighters were battling aggressively yesterday to regain control after a raging Californian fire crossed a highway that had served as a containment line for the massive blaze.
Thousands of homes have had to be evacuated. Some 20 wildfires have been raging in California.
Cooler weather had helped crews build a buffer between the wildfire and some of the thousands of homes that it threatened as it tore through drought-withered areas.
But erratic wind blew hot embers across Highway 20, north of the city of Clearlake.
"There were too many (spot fires) for us to pick up," Battalion Chief Carl Schwettmann of the Californian Department of Forestry and Fire Protection said.
"With these drought-stricken fuels, it's moving at an extremely high speed."
At least two dozen homes were destroyed over the past few days, and more than 13,000 people were urged to flee.
The fire - the largest blaze in drought-stricken California - roughly tripled in size over the weekend to almost 250 square kilometres, generating its own winds that fanned the flames and reduced thousands of acres of manzanita shrubs and other brush to barren land in hours.
Numerous other wildfires in California, Washington state and Oregon took off as the effects of drought and summer heat turned the West Coast combustible.
Californian blazes killed a firefighter last week and injured four others.