A wildfire threatening the largest grove of giant sequoias in Yosemite National Park more than doubled in size in a day, and firefighters are working in difficult terrain to protect the iconic trees and a small mountain town.
Campers and residents near the blaze were evacuated, but the rest of the sprawling park in California remained open, though heavy smoke obscured scenic vistas and created unhealthy air quality on Sunday.
“Today it’s actually the smokiest that we’ve seen,” Nancy Phillipe, a Yosemite fire information spokesperson, said on Sunday.
“Up until this morning, the park has not been in that unhealthy category, but that is where we are now.”
More than 500 mature sequoias were threatened in the famed Mariposa Grove but there were no reports of severe damage to any named trees, including the 3,000-year-old Grizzly Giant.
A sprinkler system set up within the grove kept the tree trunks moist and officials were hopeful that the steady spray of water along with previous prescribed burns would be enough to keep flames at bay, Phillipe said.
The cause of the Washburn Fire was under investigation. It had grown to nearly 6.5sq km (2.5sq miles) by Sunday morning, with no containment.
Beyond the trees, the community of Wawona, which is surrounded by parkland, was under threat, with people ordered to leave late on Friday. In addition to residents, about 600 to 700 campers who were staying at the Wawona campground in tents, cabins and a historic hotel were ordered to leave.
The giant sequoias, native in only about 70 groves spread along the western slope of California’s Sierra Nevada range, were once considered impervious to flames.
But they have become increasingly vulnerable as wildfires – fuelled by a buildup of undergrowth from a century of fire suppression and drought exacerbated by climate change – have become more intense and destructive.
Phillipe, the park spokesperson, previously said some of the massive trunks had been wrapped in fire-resistant foil for protection, but she corrected herself on Sunday and said that was not the case for this fire. However, crews have wrapped a historic cabin in the protective foil, she said.
Lightning-sparked wildfires in the past two years have killed up to a fifth of the estimated 75,000 giant sequoias, which are the biggest trees by volume and a major draw for tourists to the national park.
So far in 2022, more than 35,000 wildfires have burned nearly 1.9 million hectares (4.7 million acres) in the United States, according to the National Interagency Fire Center, well above average for both wildfires and area burned.