GILROY, Calif. -- Californians normally are treated to a kaleidoscope of colors this time of year as spring rains give rise to wildflowers and verdant hillsides. But following one of the driest March-May periods on record, the predominant color in the Golden State's wildlands is brown -- and that is fueling an unusually early start to the state's fire season.

Already, firefighters have been deployed to more than a dozen wildfires, including a massive conflagration in the rugged Santa Cruz Mountains above here that broke out on May 22 and scorched more than 4,000 acres and 31 homes before being declared under control Wednesday. State officials are so concerned about the potential for fire damage this year that Gov. Arnold Schwarzenegger issued an executive order mobilizing California's firefighting resources in early May. Normally, the fire season begins in June, but doesn't really get going until late summer.

But the real battle for the "Terminator" star and his staff isn't against Mother Nature. Forests and brush have burned with nearly clock-like regularity for thousands of years. The fight, instead, is with the humans who insist on moving into fire-prone areas -- and other regions buffeted time and again by natural disasters that people soon forget.

The Florida coast has been pounded by numerous hurricanes, including Andrew in 1992, which devastated the area south of Miami and left damages estimated at $26 billion. Yet homes get rebuilt there almost as fast as they go down. The same goes for earthquake-prone places such as San Francisco and flood zones near lakes and rivers across the country. The resort town of Guerneville, Calif., for instance, has been flooded so many times from the Russian River that some residents proudly show visitors marks inside their homes denoting how high the waters have risen.

"We are the species that goes to Las Vegas and believes probability does not apply to us, that we are going to win," said Wally Covington, a professor of fire ecology at Northern Arizona University in Flagstaff. "It's almost that mentality. It's like spinning the roulette wheel and saying, 'It will not burn while I'm here.'"

Part of that mind-set comes from what some sociologists call "the assumption of optimism" among human beings. "I don't think when somebody is purchasing a piece of property, they are thinking the fire is going to hit me," said Thomas D. Beamish, associate professor of sociology at the University of California at Davis. "They end up saying 'could happen' means it might not happen."

As people have poured into California in the past century, homes have popped up in backcountry places that are highly susceptible to fire. A look at statistics compiled by the California Department of Forestry and Fire Protection shows the problem: Between 2002 and 2006, 27,000 fires blackened 1.2 million acres and caused an estimated $1.4 billion in property damage. In the same five-year period 40 years ago, the scale of fire was roughly comparable -- 30,000 fires burned about 800,000 acres. But those fires caused about $150 million in damage, adjusted for inflation.

The stakes are going up. Last year, firestorms in Southern California swept across about a half-million acres of tinder-dry brush, destroying 3,000 homes and structures and killing 10 people. Global warming is making the situation even worse. Many scientists blame man-made climate change for unusually dry conditions that have begun to appear in California and much of the rest of the West. In Arizona, fire season is now almost year-round because of the higher temperatures, Prof. Covington said. Yet, he said, people keep building homes in remote areas all over the West.

"There's just a lot more housing in harm's way than there used to be," said Ed Sutton, a senior staff vice president for the National Association of Home Builders, an industry trade group in Washington. "People move to these places because they like the particular environment they move into. That's why you see so many people in Florida and California."

Since getting people to stop living in risky places isn't likely to happen anytime soon, government officials are trying to protect property as best they can. One example: Marin County, Calif., now requires that all new homes near wildland areas have fire-resistant rooftops. And in some areas, so many homes have been built in fire-prone places that insurers increasingly are refusing to underwrite ones in particularly hazardous zones.

Still, firefighters are on high alert as dry conditions raise the risk of fire. In the case of the so-called Summit Fire, which erupted from an as-yet unknown cause in the mountains above -- and to the west -- of this Northern California town two weeks ago, fire crews were able to respond fairly quickly because state fire officials had deployed seasonal workers only a few days earlier.

It started in the predawn hours near the top of a 2,400-foot high mountain, in chaparral and pine that had grown unusually dense because a fire hadn't hit there in more than a half century, said Bill Baxter, a state "fire behavior" analyst. Across the state -- and the West -- forests have become dangerously overgrown, the result of policies during much of the 20th century to fight fires as they erupted.

After infernos started breaking out, including a massive 1988 conflagration in Yellowstone National Park, firefighting agencies began to realize that forests need some fire to thin out trees and brush, and have been working to clear out stands. "In California, fire is as natural as rain," Mr. Baxter said.

Fanned by winds up to 45 miles per hour, the Summit Fire raced south along the ridge top, reaching a cluster of homes about a mile away within two hours -- faster than it took for fire crews to get in place. The toll was evident on an inspection Mr. Baxter took of the scene one day last week, when all that was left of one home with a sweeping ocean view was a foundation, chimney and a few household items -- including a collection of children's marbles melted on the ground.

"What they did wrong," Mr. Baxter said, pointing at blackened skeletons of chaparral a few yards from the home, "was not clear out all this vegetation when they could." People living in wooded areas are advised to create "defensible" space to keep their homes safe, such as keeping chaparral and Knobcone pine -- species that actually depend on fire to regenerate new growth -- as much as 100 feet away.

Down the road, another homeowner was luckier. Although the home was surrounded by large pines and had an exterior of wood, fire crews helped keep the flames at bay. "Thank you Firefighters for saving this sacred land and our home," read a large sign posted on the deck.

A sea breeze that kicked up a few days after the fire started provided enough humidity to help firefighters get the blaze under control. But California officials remain worried about the rest of the fire season, which is likely to last until November. And they worry what will happen if fire hits a more populated place, like 2,571-foot Mount Tamalpais in Marin County.

A major wildfire hasn't swept the mountain in decades. In 1929, a 2,500-acre fire burned about 100 homes in the town of Mill Valley. Today, there are 850 homes in that same burn area, said Rich Lopez, deputy chief of the Marin County Fire Department. In all, he said, there are as many as 5,000 homes surrounding the mountain that could be at risk from a wildfire, many situated on narrow, winding roads where fire trucks could have a hard time getting in.

"The scenario that is probably going to happen," Mr. Lopez warned, "is that we are going to get a north wind, a few sparks from a fire and that would take care of it."

Write to Jim Carlton at jim.carlton@wsj.com

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