The most destructive autumn forest fires in more than two decades -- the majority started by arsonists -- continued to rage across the southeastern United States yesterday, bringing to more than 330,000 acres the total woodlands scorched in the past two weeks and causing one death, federal officials said.

From Texas to Virginia and West Virginia, dry weather and high winds fueled flames that sent a thick haze of smoke that limited visibility and left a burning scent as far north as New York City, according to the U.S. Forest Service.

Much of the smoke in the Washington area, which limited visibility to under two miles in some places on Saturday, was dispersed by winds yesterday, said National Weather Service forecaster Tony Loriso. Officials said the smoke did not present a health hazard.

In Virginia and five other states, National Guard troops joined thousands of professional firefighters and volunteers using state-of-the-art helicopters and old-fashioned rakes to battle the blazes yesterday afternoon, hoping desperately that rains predicted for much of the Southeast today would come to their aid.

A volunteer firefighter in Laurel County, Ky., died after an apparent heart attack yesterday afternoon while battling a blaze there, officials said. His name was being withheld until relatives could be notified.

No other fatalities were reported in the fires, which struck primarily in mountainous, rural areas. However, several injuries were reported among firefighters, said Doug Williams of the National Forest Service's regional headquarters in Atlanta, who added that as many as three-quarters of the fires appear to have been ignited by thrill-seeking arsonists.

"These people are setting fires out of pure, unadulterated meanness," said Deborah Mills, a spokesman for the Virginia Department of Forestry.

Mills and other forestry officials said starting forest fires has become a ritual during dry periods in parts of southwest Virginia and elsewhere, as some residents turn to arson as an antidote to rural ennui.

Mills said that although the number of people starting the fires is small, investigators have been stymied by the reluctance of residents in remote mountain settlements to identify suspects.

The most widespread destruction has been in West Virginia, where 100,000 acres became engulfed in flames on a single day, Thursday, said forestry official Jerry Atkins. In Kentucky, 62,000 acres of forest have burned; 25,000 acres have burned in Mississippi, and 22,000 in Tennessee.

In some cases the fires have destroyed woodlands; in other cases they have done little more than clear out underbrush.

In this steep, rugged terrain of southwestern Virginia, flames yesterday were flaring up mountains faster than a man could run, said forestry spokesman Lou Southard.

Southard said yesterday's destruction was particularly frustrating coming after firefighters had contained dozens of fires from the previous week and believed that they were nearing the end of their task -- only to discover that some old fires had reignited and a new flurry of arson had begun.

"We were in pretty good shape, then they started setting them again," said Southard.

The effort to quash the fires was often akin to a military operation as helicopters from the National Guard and private contractors poured vats of water on the flames from above and "incident commanders" ordered teams of firefighters armed with rakes and leaf blowers to stake out positions on the ground.

Many firefighters, their bodies covered with soot and dripping with sweat, had stolen only a few hours' sleep in the previous three days, spokesmen said. The firefighters -- some of whom are paid, others working as volunteers -- said they could feel the heat from flames, which when they ignited branches on trees overhead made the sound of jet engines.

In general, the worst season for forest fires is spring rather than autumn, forestry officials said. One of the worst single forest fires in Virginia occurred in May 1986, when about 4,500 acres in the Shenandoah National Park were burned in a fire started unintentionally by campers.

Officials from various forestry agencies said the last fall in which damage was comparable to this year was 1964.

In the midst of yesterday's crises, officials said it was impossible to calculate the cost of fighting the fires, though it was certain to total in the millions of dollars. Damage and small-scale evacuations were reported throughout the region.

In West Virginia, a fire that spread onto railway tracks has closed since Thursday a tunnel near the Kanawha-Boone county line, shutting a key route for the transport of coal to Charleston and costing companies more than $1 million per day, said Atkins.

The widespread fires caused West Virginia Gov. Arch Moore to close the forests in 14 counties in the southern end of the state to hunters and other visitors, allowing entry only to those with homes in the woods, said Atkins. In northern West Virginia, where few fires were reported, haze from downstate was so thick that the lights had to be turned on during a daytime football game in Morgantown between West Virginia University and Virginia Tech.

Staff writer Dana Priest contributed to this report.