Firefighters are bracing for another round of hot and dry weather as they battle to save thousands of homes west of Yosemite National Park and get a handle on the Oak Fire, which ballooned over the weekend into California’s largest wildfire of 2022.
Fire crews reported their first morsel of containment Monday morning on the explosive fire, which has scorched 16,791 acres east of the old mining town of Mariposa in the Sierra Nevada foothills. The blaze stands at 10% contained — marking firefighters’ first bit of measurable progress in battling a blaze that, until now, had burned out of control while sending thousands of people fleeing for safety.
As of Monday morning, more than 3,700 people had been evacuated from communities in the path of the blaze, according to Jonathan Pierce, a Cal Fire spokesman. Thousands of structures remain threatened by the flames, and firefighters expected to spend the day continuing their efforts to keep flames away from as many houses as possible.
As nightfall descended Sunday, the fire made several runs to the south and to the east — further threatening the communities of Bootjack and Mariposa Pines, Pierce said. But its northern and western flanks have been less active — a relief for residents of the popular tourist hamlet of Mariposa.
“Overnight, the fire remained active,” Pierce said, adding that “the crews have been doing good work, especially along those active fronts.”
The official number of structures destroyed by the blaze dropped slightly from 10 to seven as damage assessment teams worked their way into the burn area, Pierce said. However, that number could change in the coming days — crews have only inspected 105 of an estimated 450 structures possibly impacted by the fire so far.
Temperatures are expected to remain in the high 80s — possibly even reaching 90 degrees — across the burn area, while humidity levels could drop into the single digits in parts of the region, said Jeffrey Barlow, senior meteorologist with the National Weather Service.
The fire ignited Friday afternoon near State Route 140 and Carstens Road in the largely rural Midpines region of Mariposa County. It quickly exploded into the state’s largest of the year — tearing through a dense, drought-weakened forest while sending up a 20,000-foot pyrocumulus cloud.
The cause of the fire remains under investigation. Myriad roads remain closed in the area, including Highway 140 from Highway 49N to Ponderosa Way.
The number of firefighters battling the blaze continued to swell Monday to 2,548, Cal Fire reported. They are using 66 dozers to cut fire lines while 17 helicopters have been assigned to drop water from the air.
A curtain of smoke stifled air across much of Yosemite National Park and the northern Sierra Nevada — leaving Yosemite Valley and its iconic granite cliffs shrouded in a thick haze on Monday morning, webcams from the Yosemite Conservancy showed.
The thickest patches of smoke extended from Groveland along Highway 120 north through Twain Harte and on to the tourist town of Arnold along Highway 4, according to the federal government’s Air Now website. Yet generally unhealthy air readings extended from Mariposa east to Mammoth Lakes and north to Plumas County and even Reno, Nev.
Southernly winds are expected to continue to send smoke from the fire drifting north over the next several days, said Cory Mueller, a National Weather Service meteorologist.
“The Sierra is pretty smoked in and pretty hazy,” Mueller said. “And unfortunately, that’s probably going to continue as that fire continues to give off smoke.”
Off-shore air flows should help keep the smoke aloft closer to the Bay Area — meaning most of it should stay at around 5,000 to 10,000 feet in the air in the coming days, said Aaron Richardson, a Bay Area Air Quality Management District spokesman. But nevertheless, some of it may drift closer to the ground, which prompted the district to issue an air quality advisory through Wednesday for people with respiratory issues.