GILROY, Calif. — A day after a mountain wildfire quickly destroyed homes and other structures, firefighters said Friday that changes in the weather were helping them hem in the central California blaze.

By dawn, the blaze was 20 percent contained after calmer winds and fog rolled into the mountains overnight. The fire was still growing, but not significantly, said Joe Waterman, a Cal Fire incident commander.

"We have a lot of forces mobilized, and we are optimistic we'll be able to hold it today," Waterman said.

About 1,400 homes remained under evacuation orders — more than 300 of them mandatory — while more than 900 firefighters and a swarm of tanker planes and helicopters continued dousing the area. More fire personnel were on their way, Waterman said.

Some residents were taken to an evacuation center set up by the Red Cross in Watsonville.

Gov. Arnold Schwarzenegger has declared a state of emergency for Santa Cruz County. No injuries have been reported.

Since Thursday morning, the wildfire has scorched close to 5 square miles.

The fire is in a mountain range that separates Santa Cruz and Santa Clara counties, a rural area about 15 miles south of San Jose that is dotted with homes.

Officials said that of the 12 structures destroyed, at least two were homes. Three schools in the area closed because of the fire, officials said.

Officials said the cause of the fire was under investigation.

Rebecca Henson, 45, was woken up by a neighbor to smoke and ash blanketing her wood cabin in Corralitos. She quickly evacuated with her dog, resigning herself to the possibility of her home burning after they left.

"That thing's gonna go up like a torch — it's got wood floors, wood ceilings, everything," Henson said as she gathered with about 75 other evacuees at a central market in another part of town. "There wasn't an official evacuation, but we're mountain folks and we're pretty used to independent living. So it didn't take too much common sense to realize this thing is close, we gotta go."

The blaze also was swirling around Maymens Flat, a tiny community of about seven homes that overlooks the Pacific Ocean and the city of Santa Cruz.

Ian McClelland, 50, who has lived there since 1987 on his 23-acre ranch, woke up Thursday morning to an orange glow on the hillside, and he immediately let his two horses free so they would have a better chance at surviving.

"There was not an opportunity to do anything," McClelland said. "There was no opportunity to put them in a trailer. So I just let them loose. They had a good chance that way."

When he returned to his property for a few minutes, nothing was left except the concrete foundations. Two of his 10 dogs also died in the blaze.

"I don't think it's hit me yet," McClelland said, his voice shaky.