Nearly 1,000 firefighters continued to wage an uphill battle against the Rim fire, which jumped a containment line and has grown in nearly every direction.
The Tuolumne County Board of Supervisors held an emergency meeting Wednesday afternoon, saying in a resolution that the fire "is now directly threatening various communities and businesses within the County and is beyond our capabilities." Members asked Gov. Jerry Brown to declare a state of emergency.
The fire, which broke out in a remote area near Groveland on Saturday, has consumed more than 16,000 acres in Tuolumne and Mariposa counties and is threatening 2,500 structures. Firefighters have struggled to protect small communities and campgrounds in the area, but nine structures have been destroyed.
It's one of 51 major uncontained wildfires burning in California, Alaska, Arizona, Idaho, Montana, Nevada, Oregon, Utah, Washington and Wyoming. More than 19,000 firefighters were fighting the fires.
On Wednesday, authorities broadened their evacuation area for the Rim fire,
adding the community of Pine Mountain Lake. Evacuations so far remain advisory rather than mandatory, said Ashley Taylor, public information officer for the United States Forest Service.
"The message we're just sending out there is that we are aggressively fighting this fire and looking for new opportunities to take it down," Taylor said.
The wind picked up on Wednesday, bringing another challenge to firefighters already dealing with intense heat and the steep, rocky terrain of the Stanislaus National Forest.
"Those are all factors that are affecting how this fire is going to behave," Taylor said. Containment remained at 5 percent.
The fire jumped a containment line along Cherry Lake Road near the firefighters' base camp. Crews managed to keep the fire along the east side of the road, Taylor said.
No injuries have been reported, though firefighters are working in higher than normal temperatures for the area.
"As you can imagine, it's extremely hot, they're in rough conditions ... and carrying packs that can weigh anywhere from 50 to 75 pounds," Taylor said. "They put their bodies through a lot of stress."
Highway 120 into Yosemite National Park remained closed, with no estimated day or time of reopening.
Several residents had assembled at evacuation centers in Sonora and Greeley Hill.
Residents kept updated on fire conditions and even the status of businesses -- Two Guys Pizza was trying to stay open as long as possible -- on the Groveland Facebook page. According to that page, the Big Oak Flat-Groveland Unified School District has canceled classes for the remainder of the week.
Grateful residents also used the page to inquire if they could bring water or anything to the firefighters. While firefighters' provisions are well-stocked, "They did say that the best thing that we can do is a smile and wave when we see the firefighters headed to the fire. Our gratitude is very important to the men and women battling the blaze and it is greatly appreciated."
Firefighters battled more than a dozen other major fires throughout the west, according to the National Interagency Fire Center in Boise, Idaho.
The center listed three fires in Montana as the nation's number one priority on Wednesday. They include a wildfire burning west of Missoula that has surpassed 13 square miles, destroyed five homes, closed U.S. Highway 12 and led to multiple evacuations. The Lolo Fire Complex, which was zero percent contained, also destroyed an unknown number of outbuildings and vehicles.
At least 19 other notable fires were burning across the state, leading Montana Gov. Steve Bullock to declare a state of emergency, which allows the use of National Guard resources ranging from personnel to helicopters.
In Oregon, a fire in the Columbia Gorge about 10 miles southwest of The Dalles grew to 13 square miles, forcing evacuations and burning a third home. The fire was 15 percent contained. Strong winds continued to fan the blaze, pushing it into the Mount Hood National Forest.
Firefighters in southwestern Oregon braced for a return of lightning storms that started a series of fires last month that continue to burn in rugged timberlands.
In Idaho, progress was reported in the fight against the nearly 169-square-mile Beaver Creek fire, which forced the evacuation of 1,250 homes in the resort area of Ketchum and Sun Valley. That fire was 30 percent contained, authorities said.
In Yellowstone National Park in Wyoming, officials reopened a 7-mile section of road closed briefly by a wildfire. As of Wednesday, the Alum Fire had burned about 12 square miles and was spreading slowly, leading park officials to make preliminary evacuation plans for a community on the shore of Yellowstone Lake.
The Associated Press contributed to this report.
Breaking News Editor Patty Guerra can be reached at email@example.com or (209) 578-2343. Follow her on Twitter, @pattyguerra.