California wildfire burns over 14,000 acres and forces evacuations as it reaches Sierra National Forest

The largest-active wildfire in California has burned more than 14,000 acres and forced thousands of people to evacuate towns across Mariposa County as it reaches the Sierra National Forest near Yosemite National Park after raging into a third day.

Governor Gavin Newsom proclaimed a state of emergency for the county on 23 July as the fire forced more than 3,000 people from their homes. The declaration will untap additional emergency resources for the region.

The Oak Fire – which was 0 per cent contained as of Saturday evening – began on Friday afternoon in the foothills of the Sierra Nevada near the town of Midpines, roughly nine miles northeast from the county seat of Mariposa.

The latest statement from the California Department of Forestry and Fire Protection says the fire – driven by extreme drought conditions – has grown “significantly” in the northern section as it moves further into Sierra National Forest.

“The fire is moving quickly. This fire was throwing embers out in front of itself for up to two miles yesterday,” Sierra National Forest spokesperson Daniel Patterson said on Saturday. “These are exceptional fire conditions.”

The fire destroyed at least 10 residential and commercial structures and damaged at least five others, while hundreds of other structures are threatened, according to Cal Fire. It has nearly doubled in size within a day, expanding from roughly 1,600 acres on Friday to more than 6,555 acres by Saturday morning. By Sunday morning, the fire encompassed roughly 14,200 acres.

Cal Fire said on Saturday that the “explosive fire behavior is challenging firefighters.”

More than 400 fire personnel, 45 fire engines and four helicopters are deployed to battle the blaze, according to Cal Fire.

Several road closures include a portion of Highway 140, partially blocking access to Yosemite National Park.

It is unclear what sparked the fire.

Meanwhile, firefighters have made significant progress against a wildfire that began in Yosemite National Park and burned into the Sierra National Forest.

The state’s second-largest active wildfire, the Washburn Fire, has burned near the southern point of Yosemite for more than two weeks, burning nearly 5,000 acres, though officials report that it is 79 per cent contained.

California has experienced increasingly larger and destructive wildfires as the climate crisis accelerates, breeding warmer and drier conditions that fuel aggressive fires.