GROVELAND, Calif. -- Each time the breeze picked up, Lee Bentley of the U.S. Forest Service squinted and took a look at the smoke cloud forming over the Rim fire.
Conditions on Sunday were eerily similar to how one of the largest wildfires in recent California history exploded in the first place.
It was first spotted on a ridge in the Stanislaus National Forest on Aug. 17 by a plane flying to another small fire. An air team was called in and dropped water until nightfall.
"Things looked good. We were feeling we had it pretty much under control," Bentley said.
But the next morning an inversion layer thick as fog kept the planes on the ground.
In the afternoon, the inversion layer lifted and the winds kicked in.
"The fire came boiling out, just cooking," Bentley said. "It was so hot it created its own weather. It was like dropping a boulder in a pond -- fire spread out in every direction."
The Rim fire, which has ballooned to nearly 134,000 acres, presents firefighters with every challenge: steep slopes, dry fuel, rugged terrain and entire communities that could be endangered depending on which way the wind blows. Every technique is in use: planes, bulldozers and thousands of firefighters trying to hold the line around summer camps, homes and towns.
On Sunday the winds were coming from the southwest, pushing the fire north towards Tuolumne City near Sonora and away from Groveland where residents returned home and reopened businesses that had been shut for a week during peak tourist season. The streets were decorated with signs thanking the firefighters.
But Bentley said the relief could be premature.
"Everybody in this town has a right to feel nervous," he said. "This fire could always turn, depending on which way the wind blows this afternoon."
More than 2,800 firefighters have been battling the blaze, which is 7% contained.