Wildfire spreads to Yosemite National Park, threatens homes

(CNN) -- A fast-moving California wildfire that is threatening thousands of structures has roughly doubled in size in a day -- to about 165 square miles -- and is now burning in part of Yosemite National Park, officials said Friday.

The Rim Fire has burned 105,620 acres, up from about 53,000 acres a day earlier, spreading east from Stanislaus National Forest to part of Yosemite, Forest Service spokesman Bjorn Fredrickson said. The fire is only 2% contained.

Although the part of the fire burning inside Yosemite is a remote wilderness area, smoke could be an issue for visitors, depending on where they are camping, he said.

The fire also is spreading west, threatening the small mountain communities of Groveland and Pine Mountain Lake just outside the Stanislaus forest.

About 4,500 structures are under threat, according to InciWeb, a federal website that collects information from agencies like the U.S. Forest Service and Bureau of Land Management.

Part of the Groveland area is under an evacuation order.

"It's crazy, and it has been for five days," Kirsten Lennon, whose home is threatened, told CNN affiliate KCRA. "Your heart's racing a little faster."

The fire still hasn't touched Groveland, which is about 120 miles east of San Francisco. Firefighters have kept the flames from pushing into the small mountain town, Fredrickson said Friday.

Authorities say the Rim Fire started in Stanislaus National Forest, just west of Yosemite, on Saturday afternoon.

The largely inaccessible and steep terrain has hampered firefighters' efforts, according to InciWeb, helping the fire grow nearly unchecked to a size now 1.5 times the area of California's capital, Sacramento.

More than 1,800 firefighters have been battling the flames on the ground and by aircraft. The cause of the fire is under investigation.

The fire had destroyed 16 structures as of Friday morning, according to InciWeb. The locations of those structures weren't listed.

California Gov. Jerry Brown declared an emergency in Tuolumne County on Thursday, when the fire's size was reported to be only about 53,000 acres.

The fire's immediate impact on Yosemite was the continued closure of Highway 120, resulting in a half-hour detour for visitors trying to enter Yosemite from the west.

The area of Yosemite that is burning is about eight miles into the park, north of Camp Mather near Lake Eleanor, Fredrickson said.

Yosemite, with hundreds of campground sites and lodging units, had nearly 4 million visitors last year, according to the National Park Service.