Yosemite fire: Hundreds more crew members added to fire lines

Another 300 firefighters have joined the massive effort to extinguish the Rim fire near Yosemite National Park that has burned more than 192,000 acres.

There are now 4,840 firefighters battling the Rim fire – the sixth largest fire in state history – which has been burning in the Stanislaus National Forest for nearly two weeks.

The blaze is 30% contained and has cost nearly $40 million to fight so far, officials said. The fire has burned about 301 square miles, an area bigger than Chicago or San Francisco.

Fire crews in Yosemite were hoping to slow advancing flames by conducting large-scale backfire operations from Hetch Hetchy Reservoir south to Tioga Road.

PHOTOS: Rim fire rages into Yosemite

The dangerous tactic involves setting fires inside containment lines to burn vegetation in the path of advancing flames and stop the spread of the blaze. Crews worked through the night Wednesday building lines along the fire’s northern face.

“They’re trying to get that line all buttoned up, widening it,” said Dick Fleishman of the U.S. Forest Service. “We’re going to be doing back burns for a week or two. Going to take awhile to get that all blackened out.”

The rate of spread of the massive fire has slowed in recent days and firefighters expect to have it fully contained by Sept. 10, officials said.

“That’s given us a greater opportunity to get in there and strengthen our containment lines,” said Daniel Berlant, a spokesman for the California Department of Forestry and Fire Protection.

Last week, the fire burned 30,000 acres in a 24-hour span and 50,000 acres in another 24 hours, Berlant said. But in the last two days, the rate of fire spread has slowed to 10,000 acres one day and 5,000 on another.

The fire has charred more than 40,000 acres in Yosemite National Park.

At least 111 structures have been destroyed by the fire, which has been burning since Aug. 17.

Among the elite hot-shot teams and professional wild-land firefighters are orange-clad convict crews trained by the California Department of Forestry and Fire Protection. The convicts are managed by CalFire crew leaders and generally do much of the arduous labor involved in cutting fire lines by hand.

About 34 inmate crews -- or some 500 firefighters -- are on the Rim fire.

Crews are also using an unmanned drone aircraft that provides real-time imagery to give fire commanders a bird’s-eye view of the 300-square-mile blaze.

The remotely piloted plane from the California Air National Guard began flying Wednesday morning. It continued on a 20-hour mission throughout the day, alerting crews to a spot fire and providing a more comprehensive fire map.

The drone, about the size of a small Cessna plane, takes off from the Victorville Airport and is operated from March Air Reserve Base in Riverside, said Lt. Col. Tom Keegan of the National Guard.

The unmanned aircraft -- equipped with infrared heat sensors and a swiveling camera -- are prized for their ability to beam real-time pictures directly to fire bosses, who can make tactical adjustments more quickly.

ALSO:

Los Angeles moves to lift decade-old ban on public murals

Hannah Anderson kidnap suspect’s sister: ‘Very difficult to believe’

Two women found dead in O.C. apartment, no visible signs of trauma

robert.lopez@latimes.com

Twitter: @LAJourno

julie.cart@latimes.com

Twitter: @julie_cart