"Crews worked all night long building containment lines," said Linda Green, a spokeswoman for Cal Fire's Sonoma-Lake-Napa unit.
Despite that work, the battle has just begun, said Marin County Sheriff's Lt. Doug Pittman, who is serving as a Cal Fire spokesman at the incident command center.
"We still have a long, long way to go," Pittman said.
The blaze started around 4:30 p.m. on Tuesday when the area was experiencing gusty afternoon winds.
"The fire quickly moved into some very steep, hilly terrain ... very difficult for firefighters to get to and unfortunately very easy for the fire to quickly run up the mountainside and get away from us," Pittman said.
The Cold Fire, in an area that saw big fires in both 2014 and 2015, prompted mandatory evacuations in two areas in the hills west of Winters: the Golden Bear Estates, a subdivision north of Highway 128 and just east of Lake Berryessa, and the Canyon Creek Resort, along Putah Creek immediately below Monticello Dam.
Rebecca Sharton of San Mateo said she and her husband were returning to the Canyon Creek Resort from an outing at Lake Berryessa when the fire broke out.
“When we got back to the camp we started packing up just in case we had to go," Sharton said Wednesday. "We thought the wind would take it the other direction, but then it hit the ridge, right where we could see it, and then it started coming down towards Canyon Creek.”
Sharton and her family were also forced to leave the campground when a fire broke out two years ago.
Highway 128 remained closed Wednesday for 7.5 miles, from Pleasants Valley Road to the Markley Cove resort. An evacuation center has been set up at the Winters Public Safety Center.
Cal Fire says a total of 700 personnel are fighting the blaze.
Along with Cal Fire, the Napa County, Winters, Dixon and Vacaville fire departments are on the fire lines. Sheriff's deputies from Napa, Solano and Yolo counties, as well as the California Highway Patrol, are assisting.
Cal Fire has brought some of the resources that have been used in the Soberantes Fire to help contain the Cold Fire, Pittman said. Firefighters from other parts of the state and possibly Oregon and Nevada are expected to assist, he said.
The weather is expected to be a major factor later Wednesday, Pittman said, as breezes increase. Fire officials are anticipating winds of up to 20 mph this afternoon.
"That is going to be a problem for us," Pittman said. "That's going to help push that fire faster and farther than we're going to want it to."
The Cold Fire is the third big fire near Monticello Dam in three years.
The night of July 4, 2014, illegal fireworks sparked the Monticello Fire along Highway 128, a few miles to the east of the dam. The blaze posed an immediate threat to Golden Bear Estates and some other residences and prompted the Canyon Creek Resort to shut down. It burned about 7,000 acres.
On July 22, 2015, the Wragg Fire started along Highway 128 just northwest of the dam. The blaze was ignited when a driver pulled a vehicle off the road into some tall grass. It burned about 9,000 acres. Golden Bear Estates, Canyon Creek Resort and other residential areas were threatened.