Rim Fire now 4th-largest in Calif. history

Laura Petrecca | USA TODAY

Show Caption Hide Caption Rim Fire still wreaking havoc It has been almost two weeks since the massive Rim Fire began not far from Yosemite National Park. Full containment is not expected for several more weeks.

Rim Fire is largest U.S. blaze in 2013%2C 4th-largest fire in state history

More than 8%2C000 firefighters are battling 6 major wildfires in Calif.

The fire is 40%25 contained

The 2-week-old Rim Fire in Yosemite became the fourth-largest wildfire in California's recorded history Sunday.

Although the fire still is growing, it was 40% contained as of Sunday, up from 35% a day earlier.

Moister air was expected to slow flames from advancing through brush and trees, giving firefighters room to set backfires, dig containment lines and to strengthen lines around threatened communities, U.S. Forest Service spokeswoman Pam Baltimore said.

For the first time since the wildfire broke out around Yosemite National Park, dense smoke began to obscure the region's majestic mountain views, park officials said.

"I'm in Yosemite Valley right now, and I cannot see the cliffs around me," spokeswoman Kari Cobb said Saturday. "The wind has shifted and smoke is impacting the entire park. We have been lucky until now."

All of the campgrounds in the valley still were full as of Saturday morning, despite the thick blanket and burning smell that permeated the area and was expected to linger until at least Monday, she said. About 8% of the park is inside the fire perimeter.

As a health precaution, visitors were being asked to scale back their outdoor recreation plans and avoid strenuous activities or even stay indoors.

As of Sunday, the blaze had scorched 222,777 acres and was threatening 4,500 residences. Eleven homes have been destroyed. Nearly 5,000 fire personnel are now battling the flames of the Rim Fire. Costs to contain the blaze could reach $47 million.

"Despite firefighters' efforts, the remote Rim Fire burning near and in Yosemite National Park continues to be very active," the California Department of Forestry and Fire Protection said in a statement Saturday morning.

"Inaccessible steep terrain and extreme fire behavior" have made suppression efforts difficult, the Incident Information System, which reports fire details, said in a statement. "Continued warmer and drier weather is forecasted for the next several days, which will elevate control concerns and slow burnout progress."

Across California, more than 8,000 firefighters are currently battling six major wildfires.

Contributing: The Associated Press