(AP) — Firefighters have significantly slowed the spread of a huge wildfire burning in a forest near Yosemite National Park, where thousands of residents from mountain communities were still under evacuation orders Monday and smoke was spreading for hundreds of miles around.

Crews “made good headway” against the Oak Fire, according to a Sunday night incident report by the California Department of Forestry and Fire Protection, or Cal Fire. “Fire activity was not as extreme as it has been in previous days.”

But smoke from the fire drifted more than 200 miles (322 kilometers), reaching Lake Tahoe, parts of Nevada and the San Francisco Bay Area, officials said.

“It’s been just horrendous with the air quality,” said Kim Zagaris, an advisor with the Western Fire Chiefs Association, which maps wildfires across the country.

More than 2,500 firefighters with aircraft support were battling the blaze that erupted last Friday southwest of the park, near the town of Midpines in Mariposa County. Officials described “explosive fire behavior” on Saturday as flames made runs through bone-dry vegetation caused by the worst drought in decades.

By Monday morning, the blaze had consumed more than 26 square miles (67 square kilometers) of forest land, with 10% containment, Cal Fire said. The cause was under investigation.

Firefighters working in steep terrain on the ground protected homes on Sunday as air tankers dropped retardant on 50-foot (15-meter) flames racing along ridgetops east of the tiny community of Jerseydale. Personnel face tough conditions that include steep terrain, sweltering temperatures and low humidity, Cal Fire said.

There are two major blazes burning in California, which is experiencing a fairly typical ramp-up to what is sure to be an active fire year once California’s infamous Santa Ana and Diablo wind events begin in September, Zagaris said.

“We’ve been fortunate. We’re not quite as far along as we were at this time last year,” he said. “But the fuels, the vegetation, are much dryer than they were last year. It’s so dry out there.”

Zagaris compared the wildfires in California this year to 2008, when few blazes burned early but a mid-summer barrage of lightning hit the state “and before we knew it there were 2,000 fires burning in the northern part of the state.”

Evacuations were in place Monday for over 6,000 people living across a several-mile span of the sparsely populated fire zone in the Sierra Nevada foothills, though a handful of residents defied the orders and stayed behind, said Adrienne Freeman, a U.S. Forest Service spokesperson.

“We urge people to evacuate when told,” she said.

Lynda Reynolds-Brown and her husband, Aubrey, awaited news about the fate of their home from an evacuation center at an elementary school. They fled as ash rained down and the fire descended a hill towards their property.
“It just seemed like it was above our house and coming our way really quickly,” Reynolds-Brown told KCRA-TV.

Gov. Gavin Newsom proclaimed a state of emergency for Mariposa County because of the fire’s effects.

Flames destroyed at least 10 residential and commercial structures and damaged five others, Cal Fire said. Assessment teams were moving through mountain towns to check for additional damage, Fouts said.

Numerous roads were closed, including a stretch of State Route 140 that’s one of the main routes into Yosemite.

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.

Pacific Gas & Electric said on its website that more than 2,600 homes and businesses in the area had lost power as of Monday and there was no indication when it would be restored.

The Oak Fire was sparked as firefighters made progress against an earlier blaze, the Washburn Fire, that burned to the edge of a grove of giant sequoias in the southernmost part of Yosemite National Park.

The latter fire, spanning a 7.5-square-mile (19-square-km) area, was 87% contained on Monday after burning for two weeks and moving into the Sierra National Forest.
___
Weber reported from Los Angeles.