In Northern California, the Park Fire has grown to more than 389,000 acres, or roughly 600 square miles.
Fire crews got help from relatively cooler temperatures and humidity and have extended containment of the fire to 18% — but more heat is forecast for the region starting later this week, and triple-digit temperatures could linger into next week.
Thunderstorms may also generate winds that drive the fire to spread erratically.
“We’re going into the heart of the fire season starting in August. We’ve got a long road ahead of us,” Cal Fire incident commander Billy See said Wednesday. He told crews, “Take advantage of the conditions we have today, double down and move forward.”
The fire, which has grown to the fifth-largest in state history, has destroyed at least 358 structures across Butte, Plumas, Shasta and Tehama counties and continues to threaten thousands more.
Across all of California, wildfires have burned more than 760,000 acres this year.
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Other large fires are burning in Oregon, Idaho, Washington and Montana.
In Colorado, one person was killed Wednesday as a wildfire burned in the town of Lyons, northwest of Denver. They were discovered in a home that was one of several that burned in the fire.
The fire was one of several burning on Colorado's Front Range. The blazes triggered evacuation orders in some mountain communities and, as in California, some were expected to grow as high temperatures arrive in the next few days.