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Yosemite wildfire doubles in size, threatens over 500 giant sequoias

The Washburn Fire burns on July 8 in Yosemite National Park’s Mariposa Grove, threatening the park’s famed sequoias. (Noah Berger/AP)

A wildfire burning in the southern part of Yosemite National Park more than doubled in size over the weekend, the latest blaze to threaten the world’s largest trees as climate change increases the intensity of fires.

The Mariposa Grove, home to more than 500 mature giant sequoias and the largest of its kind in the park, closed Thursday after visitors reported spotting smoke from the Washburn Fire near a trail.

Although the fire doubled in size over the weekend — it has burned 2,700 acres so far — it is now moving slowly, fire officials said at a briefing Monday evening.

“This fire is not moving quickly at all,” said Matt Ahearn, an operations sections chief with California Interagency Incident Management Team 13. The fire is “not fast, but hot,” he said.

Typically, it’s fires spanning hundreds of thousands of acres that cause great concern, as they can gobble up entire communities and wide swaths of forests during their rapid spread. But this fire is particularly troubling in that the trees at risk are “the root of the whole national park system,” said Cicely Muldoon, superintendent of Yosemite National Park. The sequoias in the Mariposa Grove were set aside by Abraham Lincoln in 1864, she said, predating Yosemite and the National Park Service.

Difficult terrain combined with standing dead trees fueling the blaze were complicating efforts and posing a risk to firefighters, officials said. The forest floor was blanketed in “heavy accumulations” of decomposing foliage, branches and needles, according to the incident report. Ahearn said firefighters were facing “very difficult conditions.”

Fire management staffers were working to preserve the trees by removing fuels around the sequoias and using sprinkler systems to increase humidity around the trees, among other things, said Nancy Phillipe, a Yosemite fire information spokeswoman. She told the Associated Press that first responders were using “every tactic imaginable” to contain the blaze, including airdropping fire retardant.

The fire was 22 percent contained as of Monday evening, Josh Boehm, incident commander for California Interagency Incident Management Team 13, said at the briefing.

Despite the blaze’s intensity — with large columns of smoke billowing into the sky and visible from far away — officials reassured the community that huge amounts of resources were being devoted to putting it out. Muldoon said a large stock of planes and firefighters were available because there were few other fires burning in the region.

“We’re not just sitting back and watching this thing,” said Jennifer Christie of the Bass Lake Ranger District. Boehm said officials were pursuing “full suppression, 100 percent suppression. We’re putting this one out.”

About 1,600 people — almost all tourists — were evacuated Friday from the nearby community of Wawona, Calif., and the local campground.

A wildfire in Yosemite National Park threatens over 500 sequoia trees. (Video: The Washington Post)

No injuries, structural losses or critical damage to the sequoias had been reported as of Sunday evening, Phillipe said. All the named trees, including the 209-foot Grizzly Giant and the Bachelor and Three Graces, remained safe.

“That is one of the main priorities, is protecting that grove and all the history that’s associated with it,” she said.

Sequoia trees, which are native to only the Sierra Nevada and can live for about 3,000 years, have been increasingly endangered by worsening blazes in the past few summers. Three fires since 2020 have killed 13 to 19 percent of all sequoias. Natural resource experts expect that another large-scale die-off is possible this year.

The world’s largest trees are struggling to survive climate change

The origin of the Washburn Fire is under investigation, and Phillipe said there were no obvious weather-related causes.

She told The Washington Post that the team had used fireproof aluminum wrap on the Mariposa Grove Cabin, built over 100 years ago by Galen Clark, a protector and promoter of Mariposa Grove who was appointed Yosemite’s first guardian.

From 2021: Fire threatens trees at Sequoia National Park. Fireproof blankets are the defense.

High temperatures and low humidity forecast for this weekend could complicate firefighting efforts, which already have been made difficult by numerous downed trees, Phillipe said. Trees destroyed by bark beetles, killed by climate-change-induced drought and felled by a major windstorm serve as fuel for flames.

Prescribed burns conducted periodically in Mariposa Grove in the past several years have helped slow the progress of unwanted fires, Phillipe said. In wildfire-prone areas, controlled burns get rid of fuel and clear space for firefighters to work.

Mariposa Grove, near Yosemite’s south entrance, closed in 2015 and reopened three years later after a $40 million restoration project — the largest in the park’s history. The initiative restored sequoia habitat, realigned roads and added a shuttle service from the arrival area.

After all that work, Phillipe said, park employees are not giving up on protecting the grove.

“We’re suppressing this fire,” she said. “We’re doing everything we can to put it out.”

Last year, the trees in California’s Sequoia National Park were imperiled by the KNP Complex Fire when the lightning-sparked blaze came dangerously close to the 275-foot General Sherman, the largest tree in the world by volume. The Castle Fire in 2020 burned one-third of the region’s sequoia groves.

Nearly 23,000 acres have been scorched by wildfires in California this year.

People who never considered themselves at risk from climate change are waking up to floods and fires. (Video: Monica Rodman/The Washington Post)