Haze from a wildfire covers the view of the Pacific coastline north of Big Sur. (Marcio Jose Sanchez/Associated Press)

A 19-kilometre section of California's famous Pacific Coast Highway has been closed because of a massive wildfire near the picturesque town of Big Sur, officials said Saturday.

The fire, 200 kilometres south of San Francisco, has charred almost 110 square kilometres and destroyed 16 homes since it began last week in the Los Padres National Forest.

The blaze threatens at least 500 other homes in and around Big Sur. On Friday, firefighters saved the town's Henry Miller Library from the flames.

Many of the rustic inns, restaurants and art galleries that dot the rugged coast were nearly deserted on the weekend at the height of the tourist season because of the fire threat.

Lightning strikes have been blamed for starting about 1,000 fires recently in northern California, which has seen drought conditions for the past two years.

Areas hardest hit by the lightning fires include Butte County, where fires threaten 1,200 homes; Mendocino County, with 121 fires threatening 900 homes; and Shasta-Trinity counties, where 230 homes are at risk.

Gov. Arnold Schwarzenegger asked President George W. Bush on Friday for a federal emergency declaration to free up more resources, saying most of the major fires are less than 20 per cent contained.

The blazes also have spread a smoky haze over much of the San Francisco Bay area and Central Valley, prompting air regulators to urge people to stay indoors.

With files from the Associated Press