Firefighters battled a growing wildfire at Yosemite National Park over the weekend that threatened the park’s largest grove of giant sequoias and the historic Wawona community.
The Washburn Firemore than doubled in size Saturday, growing to 1,190 acres, fire officials said.
Firefighters worked Friday and Saturday to save the historic Mariposa Grove, which houses about 500 thousand year-old giant sequoias. An area at the southern edge of the park was evacuated Friday afternoon. The fire remained 0% contained.
As of Saturday night, there were no reports of well-known sequoias in the park, such as the Grizzly Giant, being damaged.
The weekend’s weather was not looking favorable for battling the flames, officials warned — temperatures were expected to increase while humidity decreased, which are conditions that can be conducive to a fire’s spread. Forecasters expect high temperatures in the mid 80s or higher to continue for several days. A relative lack of wind, however, has helped the firefight.
The blaze was exhibiting “moderate fire behavior,” officials said, including long-range spotting — when sparks carried by the wind start new fires — and torching, when small groups of trees ignite, usually from the bottom up.
More than 200 firefighters on the scene were working to keep the fast-growing blaze from wiping out sequoias and advancing toward the historical community of Wawona, which came under mandatory evacuation orders late Friday.
Wawona was added to Yosemite National Park in 1932 and had a population of 169 in the 2010 census. The Wawona Hotel was established in 1856. Park officials said about 600 to 700 people staying in a campground, cabins and an historic hotel were evacuated Friday.
Crews at the southern entrance of the park worked Friday night to clear vegetation and create fire lines around the big trees, including the 3,000-year-old Grizzly Giant, which is one of the world’s largest. Several trees were also being wrapped with fire-resilient blankets while hoses were being laid to create a sprinkler-like system to moisten the giant trees and help them survive the flames.
Though giant sequoias, which only grow in the Sierra Nevada, have long been naturally resistant to fire, California’s increasingly intense blazes have begun to challenge that resistance. An estimated 20% of mature sequoias died in flames over the past two years.
A large pyrocumulus cloud had formed Friday above the southern edge of the park and smoke was blowing into Fresno and other parts of the San Joaquin Valley.
The cause of the fire remained under investigation. There was no obvious natural spark for the fire that broke out Thursday next to the park’s Washburn Trail, Nancy Phillipe, a Yosemite fire information spokesperson, told the Associated Press. Smoke was reported by visitors walking in the grove that reopened in 2018 after a $40 million renovation that took three years.
The southern entrance to Yosemite on Highway 41 remained closed. Other parts of the park were still open.
The Associated Press and Chronicle staff writer J.D. Morris contributed reporting.
Danielle Echeverria is a San Francisco Chronicle staff writer. Email: [email protected] Twitter: DanielleEchev