More than 2,500 firefighters supported by aircraft were battling the blaze, known as the Oak fire, which broke out last Friday near the town of Midpines, California. Officials described “explosive fire behavior” on Saturday as flames tore through lush vegetation parched by the worst drought in decades. By Tuesday morning, the fire had consumed more than 18,000 acres of land in the Sierra Nevada foothills, 26 percent contained, the California Department of Forestry and Fire Protection, or CalFire, said. At least 55 houses and structures had been burned. Map “Persistent drought, extremely dry fuels and tree mortality continue to contribute to the fire’s spread,” CalFire said Tuesday morning, but moisture levels were slightly higher, helping crews fight the blaze. By Monday, helicopters had dropped 300,000 gallons of water on the fire, the agency said. Evacuations were ordered Monday for more than 6,000 people living in a several-mile stretch of the sparsely populated fire zone, although a few residents defied orders and stayed behind, said Adrienne Freeman, a spokeswoman for the U.S. Forest Service. “We urge people to move away when they are told,” he said. The cause of the fire remains under investigation. On Monday, smoke from the wildfire blanketed views of Yosemite National Park in a thick gray haze as the air quality index (AQI) topped 250, a level classified as very unhealthy. The smoke also produced poor visibility to the north of the fire during the day and along the fire at night, CalFire said. Smoke drifted more than 200 miles (322 kilometers) to reach parts of northern California and Nevada. There are two major wildfires burning in California, which is experiencing a fairly typical uptick in what is sure to be an active fire year once California’s famous Santa Ana and Diablo wind events begin in September, said Kim Zagaris, a consultant with Western Association of Fire Chiefs, which maps wildfires across the country. “We were lucky. We’re not as far along as we were last year at this time,” he said. “But the fuel, the vegetation, is much drier than last year. It’s so dry out there.” Zagaris compared California’s wildfires this year to 2008, when few fires burned early, but a midsummer lightning storm hit the state “and before we knew it there were 2,000 fires in the northern part of the state.” Wildfires are an important part of California’s climate and essential to the health of landscapes and ecosystems across the state, but conditions have shifted, causing some blazes to become destructive. Larger and deadlier fires in recent years have increased as a history of firefighting has allowed landscapes to thicken with vegetation. The climate crisis left the West much hotter and drier, baking moisture from overgrowth and setting the stage for larger, more irregular burns. Scientists have said that weather will continue to be more extreme and wildfires more frequent, destructive and unpredictable. Many roads were closed, including a section of State Route 140 which is one of the main routes into Yosemite. The utility company Pacific Gas & Electric (PG&E) said on its website that more than 2,600 homes and businesses in the area had lost power since Monday, and there was no indication when it would be restored. The Oak fire was sparked as firefighters made progress on an earlier blaze, the Washburn fire, that burned at the edge of a grove of giant sequoias in the southernmost part of Yosemite National Park. The latest fire, which spans an area of 7.5 square miles (19 square kilometers), was 87 percent contained on Monday after burning for two weeks and moving into the Sierra National Forest.
