An oven remains standing amid ruins of a home leveled by the Valley Fire on Lincoln St. in Middletown, California September 13, 2015. [Photo/Agencies]

MIDDLETOWN, Calif.- A rapidly spreading wildfire destroyed hundreds of homes and other buildings as it roared through the northern California village of Middletown and several nearby communities, chasing thousands of residents from their homes, fire officials said on Sunday.

The so-called Valley Fire, now ranking as the most destructive among scores of blazes that have raged across the drought-stricken Western United States this summer, came amid what California fire officials described as "unheard of fire behavior" this season.

Governor Jerry Brown declared a state of emergency in areas ravaged by the blaze, and officials expanded mandatory evacuations as shifting winds sent flames and ash toward a number of towns in the hills north of Napa Valley wine country.

The Valley Fire has consumed more than 50,000 acres since erupting Saturday afternoon in rural Lake County, California, about 50 miles west of Sacramento, the state capital, fire officials said on Sunday.

Thousands of evacuees from Middletown, Cobb, Hidden Valley Lake and the Harbin Hot Springs resort gathered in shelters, restaurants and friends' houses in nearby Kelseyville and Calistoga waiting to hear about their homes, horses and dogs.