LAS VEGAS (AP) -- A patchwork of wildfires burning across more than 1,000 square miles of southern Nevada and a slice of Utah was slowed Friday, firefighters said
''We're on top of these fires,'' said U.S. Forest Service spokesman David Chevalier, who called the Mesquite and South Desert fire complexes the largest wildland blazes currently burning in the nation.
The two fire complexes, or collection of several blazes, were burning in a vast area northeast of Las Vegas that includes brittle desert grasses, mesquite, Joshua trees and mountain pines. The fires were 66 percent contained, and no structures were damaged, Chevalier said.
State and federal firefighters deployed to stop one of the blazes, a nearly 27,000-acre fire burning unchecked through remote parts of the Delamar Mountains.
''Those are wide-open spaces out there,'' Chevalier said, ''with nothing but rock formations in every direction.''
The fire posed no immediate threat to the tiny Nevada town of Alamo 18 miles to the west and about 80 miles north of Las Vegas.
Firefighters on Thursday stopped flames about nine miles from the southern Nevada railroad town of Caliente and within a mile of the 12-home hamlet of Motoqua, Utah.
More than 15 separate and merged fires have been started by lightning strikes in the area since June 22. They were burning in almost 676,000 acres overseen by the Bureau of Land Management and National Park Service in Nevada and the western edge of Utah. Officials estimate as much as half the desert, mountain and valley terrain has burned in the fire zone.
Chevalier said he was stunned Thursday to find a wispy spider web, undisturbed, strung between the leaves of a plant in a green patch surrounded by charred creosote and mesquite in the Delamar Mountains.
''The fire, as violent as it is, still left some of the most delicate stuff alone,'' he said.
Vast stretches of the wildfire area -- about two-thirds the size of Rhode Island -- include bighorn sheep and federally protected desert tortoise habitat. Chevalier said firefighters had been instructed not to disturb creatures found in burn areas, and some reported seeing tortoises still alive.
The number of firefighters, which peaked at 1,019 on Wednesday, was reduced to about 900 on Friday. They were aided by six air tankers and eight helicopters. Some firefighters have suffered dehydration, but have not been hospitalized. One suffered a broken ankle earlier in the week, and a smokejumper hurt his hip last week parachuting into the area. Estimated costs to fight the fires have reached $5 million.
Triple-digit temperatures were predicted through the weekend, but flame-fanning winds were expected to be light. Fire officials were worried that a spark from Fourth of July fireworks could start another round of blazes in southern Nevada.
State, federal and Clark County fire officials on Friday put a separate multi-agency command post at the North Las Vegas Airport to coordinate handling Independence Day holiday weekend fires in the deserts and mountains around Las Vegas.
''If we get one started by fireworks, considering the size of what we've been dealing with, the tragedy would be monumental,'' Chevalier said.
Officials fear the 2005 fire season could be a record-setter in Nevada, due to a profusion of tinder-dry vegetation that sprouted during an unusually wet winter. Already, more than 10 times the number of acres that burned last year have gone up in flames. The worst year on record saw 1.8 million acres burn in 1999.
Pam Sichting, a Forest Service spokeswoman, said about 100 firefighters still assigned to the 33,569-acre Goodsprings fire could be deployed elsewhere if fires start. The fire, about 10 miles south of Las Vegas, remained 95 percent contained Friday, with no serious injuries reported and no structures damaged. Firefighting costs were estimated at almost $2 million.
In Clark County air quality officials also were monitoring the possible health effects of a smoky haze hanging over the city from southern Nevada and Arizona wildfires.
