Update, 9:25 a.m. Wednesday: Another firefighter was injured battling the massive Ferguson Fire just west of Yosemite National Park on Tuesday.
Forest Service spokesman Jim Mackensen said Wednesday morning that he did not have additional information on the condition of the injured firefighter or the circumstances surrounding the injury. So far, one firefighter has been killed and seven injured fighting the blaze.
The fire, burning in the Sierra and Stanislaus national forests, is now reported to be 38,522 acres, or just over 60 square miles. As of Wednesday morning, the blaze was 25 percent contained.
Yosemite National Park officials are asking all visitors to evacuate the Yosemite Valley and Wawona areas of the park by noon today due to the fire.
Fire officials say a significant shift in wind patterns on Tuesday evening caused the blaze to flare up along its southern end, forcing the Mariposa County Sheriff's Office to issue new mandatory evacuations for a portion of the Lushmeadow area.
"We had a change in the wind, and the main fire started throwing spots across our line," Mackensen said. "The crews immediately jumped on the spots, but they were unable to contain them, so now we've got a fairly decent sized slop-over."
Mackensen said the new growth on the southern front — about 300 acres, as of Tuesday morning — occurred in dangerous terrain, making it difficult for firefighters to stop it.
The shift in wind patterns wasn't all bad news, though. Along the northern edge of the blaze in the Stanislaus National Forest — where firefighters have seen some significant growth in past days — the wildfire is now burning against the wind.
"It's going to slow down significantly there," Mackensen said. "And it may slow down to the point where we can actually put firefighters right on the line and put the fire out as they go."
As of Tuesday morning, the blaze was roughly 1.5-2 miles away from the park, according to fire officials. Mackensen said firefighters have started controlled burning in Yosemite West, outside of the park boundary, and they plan to begin controlled burns within Yosemite at some point soon.
Fire officials say they've been in close contact with wildlife and forestry experts as they plan controlled burns and bulldozer lines in and around the national park.
"They're actually out there with our guys," Mackensen said. "When we're cutting line with the bulldozers, they're out in front of the bulldozers looking for signs, looking for species, flagging those things. And we adjust our lines in our operations in order to protect those cultural heritages and endangered species and so forth."
Firefighters aren't expected to get any help from weather conditions today and tomorrow, with temperatures likely reaching into the triple digits. "There is potential today, with the weather conditions, for some significant fire spread," Mackensen said.
More than 3,400 personnel are fighting the blaze with 220 engines, 47 helicopters and 88 dozers.
The wildfire has not destroyed any businesses or homes, but nearly 3,500 structures remain threatened.
Update, 7:51 p.m. Tuesday: The massive Ferguson Fire, burning in very rough terrain in the Sierra and Stanislaus national forests just miles from Yosemite National Park, grew another 1,208 acres during the day on Tuesday.
The blaze has now scorched 37,795 acres — more than 59 square miles — and is 26 percent contained, according to Cal Fire.
Yosemite National Park officials announced on Tuesday that a large portion of the park, including Yosemite Valley, would be closed to visitors starting Wednesday at noon.
The Mariposa County Sheriff's Office on Tuesday evening lifted evacuation orders for Mariposa Pines residents on Scott Road from Best Road to the end of Hites Cove Road, and started repopulating the Jerseydale and Mariposa Pines communities.
Officials say the fire was relatively calm on Tuesday, and they were able to begin controlled burning of vegetation between the containment line and the fire along its eastern edge. South of the Merced River, in the Sierra National Forest, crews secured containment lines from Jerseydale to the Wawona Campground in Yosemite National Park.
Conditions are expected to be difficult for firefighters on Wednesday and Thursday, with temperatures likely to reach into the triple digits.
Original post, 3:30 p.m. Tuesday: Yosemite National Park officials are closing a large portion of the park — including the highly-trafficked Yosemite Valley — to visitors, as firefighters work to stop a massive wildfire burning just miles away.
Park spokesman Scott Gediman announced on Tuesday that all hotels, campgrounds and visitor services in Yosemite Valley and Wawona, near the southern end of the park, will be closed starting tomorrow until at least Sunday due to the Ferguson Fire.
"We're asking people here tonight to leave tomorrow morning," Gediman said. "And anyone that's incoming tomorrow will get an email or phone call stating that their reservation is cancelled."
Gediman says at least 1,000 campground and hotel reservations will be canceled. Park officials are asking all visitors in the areas to evacuate by noon on Wednesday.
The fire, burning in the Stanislaus and Sierra National Forests, has scorched through 36,587 acres — or more than 57 square miles — of dry brush and timber along steep, rocky terrain. As of Tuesday afternoon, the blaze was 25 percent contained. More than 3,000 personnel are fighting the wildfire.
According to fire officials, the Yosemite closures are being issued in order to accommodate firefighting operations in the area.
"There's gonna be a lot of traffic, fire-wise, with fire engines and everything else," said Cal Fire spokesman Richard Eagan. "So due to public safety, that's why they're closing the road."
Officials say the fire is still about 2 miles away from Yosemite's western boundary. "It's hard to say time-wise if or when it will reach the park, but it is getting closer," Eagan said.
Relatively mild conditions on Monday helped firefighters make some significant progress on the blaze, bringing containment up from 16 percent to 25 percent. "Fire behavior yesterday was very good," said US Forest Service spokesman Alex Olow. "That allowed them to get a lot of this good work done."
Olow said firefighters were able to build a containment line between Jerseydale and the park boundary at Wawona, which should allow them to be able to do some controlled-burning in that area soon. Officials say progress was also made on the northern front of the fire in the Stanislaus National Forest on Monday.
But firefighters aren't expected to get any help from the weather in the coming days, with temperatures likely to reach into the triple digits.
"Even though we've made some progress throughout the night, that doesn't mean we're out of the woods," said Ferguson Fire public information officer Joe Amador. "The dangers are still there. Weather conditions are still critical."
One firefighter has been killed and six have been injured fighting the blaze. The fallen firefighter — 36-year-old Braden Varney — was killed on July 14 after his bulldozer overturned in a steep ravine.
As of Tuesday afternoon, no homes or businesses have been destroyed, but 3,494 remain threatened.
This post contains reporting from the Associated Press.