FRESNO, Calif. (August 31, 2013)—A wind shift sent smoke from a massive forest fire burning in and around Yosemite National Park down into six San Joaquin Valley counties in Central California, officials said.
The regional Air Pollution Control District issued a health cautionary statement Friday for San Joaquin, Stanislaus, Merced, Madera, Fresno and Tulare counties, especially for foothill and mountain areas.
Officials say the impact of the 333-square-mile fire will be felt throughout the Labor Day weekend.
The fire earlier led to air quality alerts in Nevada.
Residents who see or smell smoke should stay inside, especially people with heart of lung problems, older adults and children.
The 2-week-old fire, which is now the largest to date this year in the U.S., is about 35 percent contained.
The smoke was also obscuring views in the park.
Park spokeswoman Kari Cobb said smoke from the 2-week-old blaze obscured Yosemite Valley Saturday for the first time.
The valley is home to the park's most popular landmarks.
Weather forecasts indicate the dense blanket could linger until Monday.
Meanwhile, U.S. Forest Service spokesman Mark Healey says firefighting aircraft remained grounded Saturday morning because of low visibility caused by the smoke.
Healey says officials were concerned about a 150-acre spot fire that crossed a road and prompted an evacuation order for homes near the west entrance of Yosemite.
As of Saturday, the entire wildfire has burned 343 square miles, up from 333 square miles a day earlier.