(CNN) -- Bone-dry grass and brush Saturday fed flames as more than 2,600 crew members struggled to corral a still-growing wildfire in California's Sierra foothills.
"This fire is very dynamic," said Tina Rose, spokeswoman for the multi-agency incident command. "The access to the fire has been hampering us. It is so difficult to get into those canyons."
Firefighters can be buoyed by the fact that winds appeared to have died down a bit and the massive Rim Fire's rate of growth has slowed. The fire had doubled in size from Thursday to Friday, and the total loss stood at 126,000 acres Saturday, much of it in Stanislaus National Forest.
The blaze, which was 5% contained, was spreading mostly to the east.
While the Rim Fire has consumed 12,000 acres in the northwest section of Yosemite National Park, so far it has had no direct effect on Yosemite Valley, a popular spot for tourists.
"Skies are beautiful," park spokesman Scott Gediman told CNN at midday. "It is a crystal clear blue sky in Yosemite Valley."
Still, the park has seen a few cancellations and one western entrance was closed as a precaution.
Gov. Jerry Brown on Friday issued a state of emergency in the San Francisco area because of threats to utilities.
"The San Francisco Public Utilities has been forced to shut down transmission lines," he said in a statement.
Much of San Francisco's water comes from the Hetch Hetchy Reservoir within Yosemite. There was good news on that front Saturday, as officials said there was no effect on the water quality and delivery.
About 5,500 structures were under threat, according to InciWeb, a federal website that collects information from agencies like the U.S. Forest Service and Bureau of Land Management.
Firefighters have been hampered by a lack of moisture from the sky and on the ground.
"The wind today is going to be better for firefighting, but we are still dealing with bone dry grass and brush," Rose said Saturday.
The inferno threatened the small mountain communities of Groveland and Pine Mountain Lake just outside the Stanislaus forest.
Part of Groveland was under an evacuation order.
"It's crazy, and it has been for five days," Kirsten Lennon, whose home is threatened, told CNN affiliate KCRA on Friday. "Your heart's racing a little faster."
The Tuolumne County Sheriff's Department issued evacuation advisories for the town of Tuolumne and nearby Ponderosa Hill, according to InciWeb. It was not clear how many residents were covered by the evacuation advisory.
Authorities say the Rim Fire started on August 17.
Gediman, of Yosemite National Park, said the Rim Fire's impact was restricted to the entrance closure at Highway 120 West and a backcountry section used by hikers. Temperatures were a little cooler Saturday than on Friday, he said.
The park typically has 15,000 visitors on a busy summer weekend. August sees an influx of visitors from other countries, a few of whom have called to check on conditions.
Still, there's little indication so far it's keeping many people away.
Ranger programs went on as normal Saturday and campgrounds were full.
"If somebody cancels, there are 10 people that will take their spot," said Gediman.
Yosemite, with hundreds of campground sites and lodging units, had nearly 4 million visitors last year, according to the National Park Service.
CNN's Nick Valencia reported from Yosemite National Park and Phil Gast reported and wrote in Atlanta. CNN's AnneClaire Stapleton contributed to this report.