Firefighters are wrapping fire-resistant blankets around ancient trees as blazes tear through California's world-famous Sequoia National Park.
Officials fear the fire could reach the Giant Forest, a grove of some of the world's biggest trees, within hours.
The forest hosts some 2,000 sequoias, including the 275ft (83m) General Sherman, the biggest tree by volume on Earth and about 2,500 years old.
The Colony and Paradise fires have been growing for a week.
More than 350 firefighters, along with helicopters and water-dropping planes, have been mobilised to battle the blazes.
They have wrapped several trees, including the General Sherman, with aluminium foil to protect them.