FRESNO, Calif. — Nearly a third of the huge forest fire burning in and around Yosemite National Park was contained Friday and some small communities in the mountainous area were no longer under evacuation advisories, but smoke descending down into San Joaquin Valley cities was becoming a problem.
Nearly 5,000 firefighters were battling the blaze, but in a sign of progress some were expected to be released to go home, said Daniel Berlant, spokesman for the California Department of Forestry and Fire Protection.
‘‘We continue to gain the upper hand, but there’s still a lot of work to be done,’’ he said.
The 2-week-old blaze burning in the Sierra Nevada northeast of Fresno has scorched 315 square miles of brush, oak, and pine, making it the largest US wildfire this year and the fifth-largest wildfire in modern California records. Containment was estimated at 32 percent.
Winds had been blowing dense smoke plumes northeast into the Lake Tahoe area and Nevada but a shift Friday brought them west down to the San Joaquin Valley floor.
Regional air pollution control authorities issued a health caution for San Joaquin, Stanislaus, Merced, Madera, Fresno, and Tulare counties. Residents who see or smell smoke were urged to stay inside, especially people with heart or lung problems, older adults, and children.
Evacuation advisories were lifted Thursday in Tuolumne City, Soulsbyville, and Willow Springs but remained in place for other communities, and evacuations were still mandatory along the fire’s southeastern edge.
About 75 square miles of the fire are inside Yosemite — but at some distance from the national park’s major attractions, including glacially carved Yosemite Valley’s granite monoliths and towering waterfalls.
Park officials expect about 3,000 cars a day to pass through gates during the long Labor Day weekend instead of the nearly 5,000 that might typically show. The fire has caused some people to cancel reservations in the park but those vacancies have been quickly filled, officials said.
It’s a familiar pattern of panic, cancellation, and rebooking in the rugged national park that has been shaped by all manner of disaster. In years past, when boulders tumbling from 3,000-foot granite monoliths have sent tourists scrambling, or when a mouse-borne illness killed tent cabin guests, cancellations poured in.
But the park never has enough lodging for the 4 million tourists who visit annually, so vacant rooms rarely go unfilled for long.
That’s not the case in nearby Groveland, a scenic Gold Rush community along a road that carries 2.2 million cars into the park every year. Early on, fire tore along Highway 120, forcing its closure and cutting off the town’s lifeblood.
Since then, the historic hamlet has been the dateline on scores of ominous news stories describing the inferno that has long since chewed its way north. The notoriety has taken a toll.
‘‘I laid off all my girls’’ Wednesday, said Laura Jensen, owner of the Firefall Coffee Roasting Co. ‘‘This has totally drained us. It’s like winter when we slow down and take care of the locals, but this should be our busiest time of the year.’’
Making matters worse for Groveland was Thursday’s fire-forced cancellation of the Strawberry Music Festival, which draws 20,000 bluegrass lovers to town every Labor Day weekend.
‘‘We’re coming into the crescendo of our season,’’ said Doug Edwards, owner of the Hotel Charlotte. ‘‘Our hotel should be completely full.’’
The impact is being felt as far north as Lake Tahoe, where thick smoke settled this week in the alpine basin that draws outdoor enthusiasts from around the world, affecting everything from hotel reservations to bicycle rentals.
The sky was clear Thursday, but tourists had yet to come back. ‘‘It has dropped off drastically the past week,’’ said Travis McCoy of Camp Richardson Mountain Sports Center on the lake’s south shore. His usual rental income of up to $3,000 daily has fallen to less than $500.
Some hotels and motels at South Lake Tahoe were experiencing as much as a 10 percent to 20 percent drop in business, with less of an impact at larger hotel-casino properties, said Carol Chaplin, executive director of the Lake Tahoe Visitors Authority. But she said there were signs of improvement as the holiday weekend neared.
‘‘We’ve got blue skies. We’ve got the lake back. It’s the best it has been in a week,’’ she said.
The cost of fighting the fire reached $47 million, including firefighters from 41 states and the District of Columbia and significant aviation resources including helicopters, a DC-10 jumbo jet, and military aircraft equipped with the Modular Airborne FireFighting System. Aircraft have dropped 1.7 million gallons of retardant and 1.4 million gallons of water.