Marcio Jose Sanchez, Associated Press
Acting Capt. Dave Craddock surveys a fire-ravaged forest in Big Sur, Calif., Thursday. The wildfire has burned at least 16 homes and threatens another 500.

BIG SUR, Calif. — Flames from a huge wildfire burning through a national forest inched toward the scenic tourist town of Big Sur, where firefighters rushed Thursday to protect historic structures and hundreds of homes.

As the lightning-sparked blaze crept closer to California's coastal Highway 1, fire engines stood guard next to rustic buildings as thick smoke and ash drifted over the Pacific Ocean.

Firefighters fortified their lines near populated areas but were letting the fire rage nearly unchecked through steep mountain forests as flames torched massive redwoods and sent them toppling.

The blaze in the Los Padres National Forest was only 3 percent contained and had burned nearly 37 square miles near the coast about a mile south of Big Sur, officials said. The fire has destroyed 16 homes since breaking out Saturday.

Authorities asked residents to evacuate 75 homes along a ridge threatened by the blaze. About 500 homes were threatened in all.

"This is not going away anytime soon," said Mark Savage, a spokesman for the U.S. Forest Service. "We're gearing up as opposed to gearing down."

Authorities closed a long stretch of the Pacific Coast Highway threatened by the blaze, shutting off access to several lodges, restaurants and art galleries that depend on tourist traffic. Motorists who had planned to drive south along the coast were forced to turn around.

Dutch travelers Joost Ueberbach, 28, and Gemma Arts, 27, wanted to drive through Big Sur on their way to Los Angeles from San Francisco but ran into the roadblock Thursday.

"We knew there was a fire somewhere, but we didn't know the road was blocked," Ueberbach said. "We had hoped to see the nice views of the coastline. I guess it's just bad luck."

A popular tourist spot along the towering coastal cliffs, Big Sur is also a storied destination for generations of American writers and artists.

Fire crews on Thursday beat back flames that threatened a small roadside library named after "Tropic of Cancer" author Henry Miller, who spent the last years of his life at Big Sur.

Just down the road, crews maintained fire lines and doused flames near the wooden cabins of Deetjen's Big Sur Inn, which had been evacuated early Sunday morning.

Hal Newell, who lives in a small wooden house on a ridge just above the bed and breakfast, dropped by to check on his home for the first time since he and his family were forced to flee five days earlier.

"I feel real glad to still have a place to live," said Newell, who has lived in Big Sur since he was born in 1938.

The National Weather Service predicted more dry lightning toward the end of the week, although forecasters did not expect as severe an electrical storm as occurred last weekend, when nearly 8,000 lightning strikes sparked about 800 fires across Northern California.

The state's largest fire, about 20 miles east of Big Sur in a more remote area of the Los Padres forest, also continued to vex firefighters, having scorched more than 92 square miles and destroyed two homes. The blaze, sparked by a campfire on June 8, was about 71 percent contained.

Monterey County sheriff's officials said mandatory evacuation orders were in place for both fires, but could not specify how many people were forced from their homes.

Gov. Arnold Schwarzenegger visited to assess the damage and said he has called in the National Guard to help fight the fires.

"The fact is that when you have that many fires — and there are still 700 fires left all over the state of California — you get stretched thin with the resources," Schwarzenegger said.

The governor also visited Butte County, where 29 fires covering about 11 square miles raged were threatening 1,200 homes. The blazes, which were only 5 percent contained, cropped up just as the county was recovering from a fire that charred 74 homes and 36 square miles earlier this month.

Areas hit the hardest by the lightning storm also included Mendocino County, where 106 fires have burned more than 33 square miles and destroyed two homes and the Shasta-Trinity Forest, where more than 150 fires have burned about 34 square miles and forced several evacuations.

Altogether, the region's wildfires had burned almost 250 square miles despite the efforts of more than 12,000 firefighters and crews from 41 states.