High temperatures, low humidity and wind thwarted efforts to contain a fire near Foresthill, which grew to at least 800 acres Thursday, one of the largest wildfires in the Sacramento region this season.
As of early evening, as many as 150 homes were reported threatened, though no structures had burned, and about 300 people had been evacuated.
State fire officials reported that 1,800 firefighters were battling the blaze or en route, after additional personnel and equipment were requested from as far away as Southern California.
Dubbed the Robbers fire, it began about 3:20 p.m. Wednesday near the east bank of the north fork of the American River and burned eastward, toward Iowa Hill. As of Thursday evening, the fire was reported spreading to the southeast and northeast.
Fire officials had worried that it might head west, toward more populated areas.
"Our concern is the possibility of it getting in the American River Canyon and jumping the river," said Brice Bennett, a California Department of Forestry and Fire Protection spokesman. "That would give it the potential to go to Colfax."
Evacuees gathered at the Foresthill Veterans Memorial Hall, chosen by Placer County's Office of Emergency Services as an evacuation center.
Kathy Shawl of Foresthill said she and her family left their home Wednesday before the evacuation order.
"We knew that fire travels uphill and the fire was down below us," Shawl said, adding that her father was a firefighter.
They also knew it would take time to get out with their animals three horses, four cats, three dogs and three parrots. The toughest part, Shawl said, was rounding up the cats. They had to leave behind an uncooperative goat.
Shawl said her husband, Dave, was working, so it was left to her and daughters Mavis, 16, and Vivian, 20, to bring out what they could.
"It's our dream house. We built it out of nothing. It's really scary, but this is what matters," Shawl said, indicating her children and animals.
Thursday's weather did not favor firefighters. After reporting the fire 20 percent contained, with 317 acres burned in the morning, fire officials announced by late afternoon that that fire had grown to 700 acres, and was only 10 percent contained.
A distinctive column of smoke developed by afternoon, indicating that fire activity had picked up, Bennett said. A 5 to 7 mph wind added to the firefighting challenge. Bennett said the fire had spread rapidly Wednesday even without wind.
Mike Poulos had to flee his home on Yankee Jims Road, one of the first areas threatened by the fire, along with his wife, two daughters, his son and son-in-law. They had to leave their cats behind.
Poulos had driven to the top of a nearby ridge where he could see the smoke.
"It's bad," he said. "I've never seen anything like it."
For evacuees there was a sense of helplessness. "I'm more confused than anything else," Poulos said. "I don't know what to do."
About 200 people packed the evacuation center Thursday night to receive an update from fire officials. The biggest question for most was the safety of their homes.
Eighty fire crews were fighting the Robbers fire with 192 engines, nine air tankers, nine helicopters, 35 bulldozers and 24 water tenders, and Bennett said more resources were on the way.
For evacuation-related information, call the Placer County Office of Emergency Services at (530) 886-5310. For fire information, phone Cal Fire's Auburn call center, (530) 823-4083.
Elsewhere in Northern California, the Sites Complex, five fires totaling 4,185 acres west of Maxwell, was declared 100 percent contained Thursday. Also in Colusa County, the Mill fire, 10 miles west of Stonyford, in the Mendocino National Forest, was reported 40 percent contained with 18,985 acres burned.