A fast-moving brush fire near Yosemite National Park has exploded in size into one of California's largest wildfires of the year, prompting evacuation orders for thousands of people and shutting off power to more than 2000 homes and businesses.
The Oak Fire started on Friday afternoon southwest of the park near the town of Midpines in Mariposa County and by Saturday morning had rapidly grown to 26.5 square kilometres, according to the California Department of Forestry and Fire Protection.
It 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 park.
Evacuation orders were put in effect Saturday for more than 6000 people living in the sparsely populated, rural area.
By Saturday morning, the fire had destroyed 10 residential and commercial structures, damaged five others and was threatening 2000 more structures, Cal Fire said.
The blaze prompted numerous road closures, blocking one of the main routes into Yosemite.
More than 400 firefighters, along with helicopters, other aircraft and bulldozers, battled the blaze, which was in a sparsely populated, mostly rural area of the Sierra Nevada foothills.
Hot weather, low humidity and bone dry vegetation caused by the worst drought in decades was fuelling the blaze and challenging fire crews.
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.
Meanwhile, firefighters have made significant progress against a wildfire that began in Yosemite National Park and burned into the Sierra National Forest.
The Washburn Fire was 79 per cent contained Friday after burning about 20 square kilometres 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 25 square kilometres.
The fire 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, the world's largest trees by volume.