Wildfire threatens Yosemite National Park

A Hotshot fire crew member rests near a controlled burn operation at Horseshoe Meadows as crews continued to fight the Rim Fire near Yosemite National Park on Sept. 4, 2013. The fire, which was started Aug. 17 when a hunter's illegal campfire burned out of control, is now the third-largest blaze in state history, authorities said

A fire crew member uses a flare pistol to ignite backfires as they fight the Rim Fire near Yosemite National Park in California on Sept. 2.

A member of the BLM Silver State Hotshot crew uses a drip torch to set back fires on the southern flank of the Rim Fire in California on Aug. 30.

Half Dome looms over Yosemite Valley on Aug. 28 in Yosemite National Park. As the Rim Fire continued to burn on the western edge of Yosemite National Park, the valley floor of the park remained open.

A Merced Grove cabin, next to the giant sequoias, is covered in metal foil by CalFire crews trying to protect structures from the Rim Fire burning through trees near Yosemite National Park, Calif., on Aug. 27.

A firefighter stands on top of a fire truck at a campground destroyed by the Rim Fire near Yosemite National Park, Calif., on Monday, Aug. 26. Crews working to contain one of California's largest-ever wildfires gained some ground Monday against the flames threatening San Francisco's water supply, several towns near Yosemite National Park and historic giant sequoias.

NASA astronaut Karen Nyberg transmitted this image of smoke wafting from California's Rim Fire, as seen from the International Space Station, via Twitter on Aug. 26. North is to the left in this image.

The Rim Fire burns along Highway 120 near Yosemite National Park, Calif., on Aug. 25. With winds gusting and flames jumping from treetop to treetop, hundreds of firefighters have been deployed to protect communities in the path of the Rim Fire raging north of Yosemite National Park.

Sgt. Chris Boni, crew chief from the 1-140th Aviation Battalion (Air Assault) from Los Alamitos Joint Training Base, releases water to help control the Rim Fire below, near Yosemite National Park, Calif., on Aug. 22. The UH-60 Black Hawk Crews are battling the Rim wildfire, one of the largest in California history, in support of the U.S. Forest Service and CAL FIRE.

The drought-fueled Rim fire burns in central California, near Yosemite National Park. Red outlines indicate hot spots where MODIS detected unusually warm surface temperatures associated with fires. Winds blew a thick smoke plume toward the northeast.

U.S. Fish and Wildlife Service firefighter Corey Adams sits on a tree stump as he monitors the Rim Fire on Aug. 25, 2013 near Groveland, Calif. The Rim Fire continues to burn out of control and threatens 4,500 homes outside of Yosemite National Park. Over 2,000 firefighters are battling the blaze that has entered a section of Yosemite National Park and is currently 7 percent contained.

Inmate firefighters walk along state Highway 120 as firefighters continue to battle the Rim Fire near Yosemite National Park, Calif., on Aug. 25. Fire crews are clearing brush and setting sprinklers to protect two groves of giant sequoias as a massive week-old wildfire rages along the remote northwest edge of Yosemite National Park.

A burned car sits on the side of the road after being consumed by the Rim Fire on Aug. 25, 2013 near Groveland, Calif.

Flames from the Rim Fire jump Highway 120 outside of Yosemite National Park in Groveland, Calif. on Aug. 24. With the fire threatening resources used to provide water and electricity to San Francisco, on Friday California Governor Edmund G. Brown Jr. extended a state of emergency to cover the city and county of San Francisco.

Emily Dobson, who says she had to evacuate her home in Groveland, thanks firefighters fighting the Rim Fire near Jamestown, Calif., on Aug. 24.

Cows walk through a section of forest that was burned by the Rim Fire outside of Camp Mather on Aug. 24, near Groveland, Calif.

A firefighter uses a hose to douse the flames of the Rim Fire on Aug 24 near Groveland, Calif.

A plume of smoke rises from a ridge as the Rim Fire approaches Yosemite Lakes on Aug. 23 near Groveland, Calif.

Fresno County firefighters and engines wait in Ackerson Meadow safety zone while fire heads to Mather Camp adjacent to Yosemite National Park on Aug. 23.

A Tuolumne County sheriff's deputy looks at an incident map of the Rim Fire on Aug. 22, in Groveland, Calif.

A DC-10 air tanker drops fire retardant on a ridge ahead of the advancing Rim Fire on Aug. 22, in Groveland, Calif.

Los Angeles County firefighters hike in on a fire line on the Rim Fire near Groveland, Calif., Aug. 22.

A firefighter from the Colorado based Long Canyon Fire Department monitors a back fire while battling the Rim Fire on Aug. 22, in Groveland, Calif.

A U.S. Forest Service firefighter monitors a radio while battling the Rim Fire on Aug. 22, in Groveland, Calif.

A log smoulders after trees were burnt by the Rim Fire near Buck Meadows, Calif., on Aug. 22.

Firefighters from Ebbetts Pass Fire District monitor a back fire while battling the Rim Fire on Aug. 21, in Groveland, Calif.

Fire consumes trees along US highway 120 as the Rim Fire burns out of control on Aug. 21, in Groveland, Calif.

A rabbit runs across the road as a firefighter from Ebbetts Pass Fire District monitors a back fire as he battles the Rim Fire on Aug. 21, in Groveland, Calif.

Fire consumes trees along US highway 120 as the Rim Fire burns out of control on Aug. 21, in Buck Meadows, Calif.

A Smokey the Bear sigb is posted along US highway 120 as the Rim Fire burns out of control on Aug. 21, in Groveland, Calif.