California firefighters continued to battle a massive wildfire in Sierra National Forest on Sept. 10 that burned through a grove of giant sequoias and set some of the ancient trees on fire.

The Garnet fire, burning in Fresno County, was ignited by lightning at about 1 p.m. on Aug. 24, according to the U.S. Forest Service.

Firefighters with tree-climbing experience were being sent to fight the flames burning in Sierra National Forest in Fresno County, a spokesperson for the fire reported.

Fire officials reported extensive tree mortality and challenging firefighting conditions.

Sequoias grow naturally in a 260-mile belt of the forest along the western slope of the Sierra Nevada mountains in California. The massive and ancient trees can grow more than 300 feet tall, with some as old as 3,000 years.

To protect the trees, fire crews have laid sprinkler lines to increase ground moisture, wrapped tree trunks with fire-resistant foil blankets, raked flammable material away from them, and patrolled the area looking for hot spots, according to Jay Tracy, spokesperson for the fire.

“These trees are near and dear to the forest and to our community, and we want to do our best to protect them,” Tracy said.

About 2,700 fire personnel were dedicated to fighting the Garnet fire, which had grown to nearly 57,000 acres on Sept. 10.

The fire was 15 percent contained and was burning in dense, matted grasses at lower elevations, fire officials reported.

“The fire is now established ... with extensive tree mortality along the north fork of the Kings River, within an area lacking a recorded fire history,” the Forest Service reported.

The fuel conditions were challenging to control and presented significantly increased hazards to fire personnel, according to the service.

The fire was still active and burning uphill, officials reported.

“The fire is burning in an area with a significant number of dead and down trees from the 2012 bark beetle epidemic and the 2015 Rough Fire, which contributes to higher intensity fire behavior,” the Forest Service stated in a morning update.

Parts of the forest have been closed to the public during the fire.

The Fresno County Sheriff had issued evacuation orders and warnings, along with road closures for areas affected by the Garnet fire.

Fire officials plan to host a virtual community meeting at 5:30 p.m. Sept. 10 to provide an update on the current situation and address questions.

The Garnet fire burned in the Sierra National Forest on Sept. 7, 2025. (Josh Leutzinger/U.S. Forest Service)

The Associated Press contributed to this report.