The California Department of Forestry and Fire Protection confirmed one fatality in the wildfire north of San Francisco that raced through dry brush and exploded in size within hours.
Officials also counted 400 homes, two apartment complexes and 10 businesses destroyed by the flames, department spokeswoman Lynn Valentine said.
The devastation comes after a separate wildfire to the southeast destroyed at least 81 homes.
Whole blocks of houses were burned in parts of the town of more than 1,000 residents that lies about 32 kilometres north of the famed Napa Valley.
On the west side of town, house after house was burned to their foundations, with only charred appliances and twisted metal garage doors still recognisable.
Firefighters yesterday could be seen driving around flaming utility poles to put out spot fires.
Wind gusts that reached up to 48 kph sent embers raining down on homes and made it hard for firefighters to stop the Lake County blaze from advancing, California Department of Forest Protection spokesman Daniel Berlant said.
There's no official tally of the destruction yet because firefighters are focused on new evacuation orders and on residents' safety, he said.
People were ordered yesterday to evacuate a stretch that included Clear Lake Riviera, a town with about 3,000 residents, Cal Fire said.
George Escalona told The Associated Press that in some areas of town "there is nothing but burned houses, burned cars," adding that all he had left were the clothes he was wearing.
Gov Jerry Brown yesterday declared a state of emergency to free up resources.
