The largest wildfire in the US has torched more dry forest in Oregon – one of dozens of major blazes burning across the west of the country as critically dangerous fire weather looms in the coming days.
The Bootleg Fire just north of the California border has grown to more than 476 square miles, an area about the size of Los Angeles.
Erratic winds fed the blaze, creating dangerous conditions for firefighters, said John Flannigan, an operations section chief on the 2,000-person force battling the flames.
“Weather is really against us,” he said. “It’s going to be dry and air is going to be unstable.”
Authorities expanded evacuations that now affect around 2,000 residents of a largely rural area of lakes and wildlife refuges.
The blaze, which was 22% contained, has burned at least 67 homes and 100 outbuildings while threatening thousands more.
At the other end of the state, a fire in the mountains of north-east Oregon grew to more than 17 square miles by Sunday.
The Elbow Creek Fire that started on Thursday has prompted evacuations in several small, remote communities around the Grande Ronde River about 30 miles south-east of Walla Walla, Washington. It is said to be 10% contained.
Natural features of the area act like a funnel for wind, feeding the flames and making them unpredictable, officials said.
In California, a growing wildfire south of Lake Tahoe jumped a major road, prompting more evacuation orders, the closure of the Pacific Crest Trail and the cancellation of an extreme bike ride through the Sierra Nevada.
The Tamarack Fire, which was sparked by lightning on July 4, had charred nearly 29 square miles of dry brush and timber as of Sunday morning.
The blaze was threatening Markleeville, a small town close to the California-Nevada state line. It has destroyed at least two structures, authorities said.
A notice posted on Saturday on the 103-mile Death Ride’s website said several communities in the area had been evacuated and ordered all bike riders to clear the area. The fire left thousands of bikers and spectators stranded in the small town and racing to get out.
Kelli Pennington and her family were camping near the town on Friday so her husband could participate in his ninth ride when they were told to leave. They had been watching smoke develop over the course of the day, but were caught off guard by the fire’s quick spread.
“It happened so fast,” Ms Pennington said. “We left our tents, hammock and some foods, but we got most of our things, shoved our two kids in the car and left.”
About 500 fire personnel were battling the flames on Sunday, “focusing on preserving life and property with point protection of structures and putting in containment lines where possible,” the US Forest Service said.
Meteorologists predicted critically dangerous fire weather with lightning possible in both California and southern Oregon.
“With the very dry fuels, any thunderstorm has the potential to ignite new fire starts,” the National Weather Service in Sacramento, California, said on Twitter.
Extremely dry conditions and heat waves tied to climate change have swept the region, making wildfires harder to fight.
Climate change has made the US west much warmer and drier in the past 30 years and will continue to make weather more extreme and wildfires more frequent and destructive.