The Electra fire in Northern California's Amador and Calaveras counties grew slightly Wednesday, from 3,900 to 4,112 acres, as firefighters increased containment to 40%, according to the California Department of Forestry and Fire Protection.
Firefighters were also able to gain control, defined as no longer having smoke activity or hot spots within the fire perimeter, over 17% of the blaze, Cal Fire said late Wednesday afternoon.
But about 8,000 Pacific Gas & Electric customers in Amador and Calaveras counties remained without power Wednesday due to the fire, and many were still under mandatory evacuation orders.
The Electra fire, one of the largest wildfires this season, ignited Monday afternoon near the North Fork of the Mokelumne River and spread quickly amid dry brush and steep terrain, according to Cal Fire officials. The fire remained active for the first half of the night, but humidity in the early morning hours helped limit its activity, officials said.
“The biggest issue right now is the terrain and the topography,” said Electra fire spokesperson Chris Dargan on Wednesday morning. He said much of the fire is burning in a gully that is a challenge for crews to access.
The blaze ignited not far from PG&E's Electra powerhouse, a hydropower facility, but company spokesperson Megan McFarland said it's her understanding that "PG&E was not involved in the ignition.”
The cause of the fire remains under investigation.
PG&E has restored power for about 7,000 customers since the start of the blaze, McFarland said. The company has also de-energized several distribution lines for firefighter safety, and has 11 Safety and Infrastructure Protection Team engines working to treat potential equipment issues from the fire, she said.
On Monday, about 100 people were evacuated from the PG&E hydropower facility, McFarland said.
A mandatory evacuation has not changed since Tuesday afternoon, Dargan said, and many residents in Amador and Calaveras counties are still under evacuation orders and warnings.
Two evacuation centers have been set up at the Italian Picnic Grounds on California State Road 49 in Amador County, and in Calaveras County at the Mountain Oak School on Old Oak Road in San Andreas. A prior evacuation shelter at the San Andreas Town Hall has been closed.
Shelters for large and small animals are also available at the Amador County Fairgrounds.
At least one firefighter was injured in the fire response, but a Cal Fire spokesperson said the injury was minor.
More than 1,300 firefighters continue to battle the blaze, as of Wednesday morning.
The fire is one of the largest Cal Fire has faced this year, exceeded only by the 5,800-acre Lost Lake fire that burned in Riverside County in May and the 4,100-acre Airport fire that burned in Inyo County in February, according to the agency.
Times staff writer Gregory Yee contributed to this report.
This story originally appeared in Los Angeles Times.