(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 nearly 106,000 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.
The fire has burned 11,000 acres in a remote wilderness area of Yosemite and has had no direct effect on the park's tourist-heavy Yosemite Valley, park Ranger Kari Cobb said.
Although smoke could become an issue in parts of the park, Yosemite Valley -- 20 miles away -- was clear Friday morning because winds were pushing the smoke and fire away, she said.
"(The fire) is in an area that would not affect park operations," she said.
Meanwhile, 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.
Meanwhile, about 70 miles to the east of Groveland, evacuation advisories were issued Friday for the town of Tuolumne and nearby Ponderosa Hill by the Tolumne County Sheriff's Department, according to InciWeb. It was not clear how many residents were covered by the evacuation advisory.
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 included the continued closure of Highway 120, resulting in a half-hour detour for visitors trying to enter the park from the west.
In Yosemite, the fire was about 4 miles west of the Hetch Hetchy Reservoir, near Lake Eleanor, Cobb said. Those areas were evacuated earlier in the week as a precaution, though no visitor or ranger structures are in danger, she said.
"Visitors who have planned to come this weekend should still come. Yosemite Valley is not affected by the fire," Cobb said.
Yosemite, with hundreds of campground sites and lodging units, had nearly 4 million visitors last year, according to the National Park Service.