A state of emergency has been declared in California’s Mariposa County due to a massive wildfire near Yosemite National Park.
The so-called Oak Fire exploded in size on Saturday into one of the state’s largest wildfires of the year, prompting evacuation orders for thousands of people and shutting off power to more than 2,000 homes and businesses.
The fire started on Friday afternoon south-west of the park, near the town of Midpines, and by Saturday had grown to nearly 19 square miles, according to the California Department of Forestry and Fire Protection (Cal Fire).
Evacuation orders were put in effect on Saturday for more than 6,000 people living across a several-mile span in the sparsely populated, rural area, said Daniel Patterson, a spokesman for the Sierra National Forest.
More than 400 firefighters are battling the blaze, along with helicopters, other aircraft and bulldozers, facing tough conditions due to hot weather, low humidity and bone-dry vegetation caused by the worst drought in decades, Mr Patterson said.
“The fire is moving quickly,” he said. “This fire was throwing embers out in front of itself for up to two miles yesterday. These are exceptional fire conditions.
The cause of the fire is under investigation.
Cal Fire said in a statement that “explosive fire behaviour is challenging firefighters”, describing the Oak Fire’s activity as “extreme with frequent runs, spot fires and group torching”.
By Saturday morning, the fire had destroyed 10 residential and commercial structures, damaged five others and was threatening 2,000 more structures, Cal Fire said. The blaze prompted numerous road closures, including a shutdown of Highway 140 between Carstens Road and Allred Road – blocking one of the main routes into Yosemite.
The Oak Fire erupted as firefighters made progress against an earlier blaze that burned to the edge of a grove of giant sequoias in the southernmost part of Yosemite.
The Washburn Fire was 79% contained on Friday after burning about 7.5 square miles of forest. It was one of the largest fires of the year in California, along with the Lost Lake Fire in Riverside County that was fully contained in June at nine square miles.
Washburn broke out on July 7 and forced the closure of the southern entrance to Yosemite and evacuation of the community of Wawona as it burned on the edge of Mariposa Grove, home to hundreds of giant sequoias.
California has experienced increasingly larger and deadlier wildfires in recent years as climate change has made the West much warmer and drier over the past 30 years. Scientists have said weather will continue to be more extreme and wildfires more frequent, destructive and unpredictable.