SONOMA — California Gov. Jerry Brown has declared a state of emergency in Napa, Sonoma and Yuba counties because of wildfires that the governor says are threatening thousands of homes.

Brown issued the declaration on Monday, as multiple fires forced people to evacuate their homes.

Napa County Fire Chief Barry Biermann said more than 50 structures had been destroyed, but there were no reports of injuries or deaths.

Residents describe terrifying middle-of-the-night scrambles to flee from raging wildfires.

Biermann says the fires had burned more than 68 square miles (176sq. kilometers).