The fire in Northern California has burned more than 350,000 acres. In Oregon, firefighters were working to contain the Durkee fire, which has covered at least 288,000 acres.
The Park fire in Northern California nearly doubled in size on Friday night, becoming the largest active blaze in the country, as firefighters raced to contain scores of blazes across the American West.
Federal officials say active fires have burned more than 2 million acres. With smoke darkening the skies, authorities in California and Oregon refined evacuation zones and urged people to be prepared to flee with little notice. Already this week, thousands of people have been told to evacuate, and the smoke has prompted air quality alerts across the Pacific Northwest and Mountain West.
The sprawling fire in California has expanded rapidly to more than 350,000 acres in Butte, Tehama and Shasta Counties, near Chico, fire officials said. They added that the fire was expanding by as much as 5,000 acres an hour.
How it starts vs how it can continue are two different things.
As it gets hotter, forests get drier. Prolonged drought periods make for more leaves, more brush - more fuel for fires on the ground.
Most wildfires these days start out due to something caused by people - a flaming car is one example, along with less blatant things like poorly handled campfires, poorly maintained or damaged power lines, burning off brush, even a tossed cigarette in the right conditions.
Climate change is increasing the scope of wildfires regardless of cause.