The Bootleg blaze in southern Oregon has swelled to become the biggest among scores of current bushfires engulfing the western US and is expected to grow as dryness and heat thwart fire crews.
Bootleg is about 30 per cent contained, the US Forest Service says, and officials have ordered mandatory evacuations of some areas. While firefighters are battling to control its southern flank, the agency expects “significant acreage increase” on its eastern side.
Historic droughts and searing heat exacerbated by climate change have touched off a cascading series of bushfires, played havoc with electric grids and created water shortages for farmers and communities throughout the western US.
Bootleg comes on the heels of last year’s fires that amounted to the most expensive disaster in Oregon history. A study found that June’s deadly Pacific North-West heatwave was intensified by greenhouse gas pollution.
The fire now ranks as the fourth largest in the state in records dating to 1900 and could move up the list as it continues to expand, said Courtney Travis, a senior meteorologist with AccuWeather.
She said the area is not expected to receive any rain soon and temperatures will climb through the week, fuelling the blaze. It could be weeks before firefighters have it contained, she said.
There are currently 83 large fires burning in the US with all but one are in the west.
Through July 19, more than 35,000 wildfires have burnt more than 2.5 million acres across the US, the US National Interagency Fire Centre said. While the number of fires is above the 10-year average, the amount of acreage is below.
Despite its size, the Bootleg blaze has not affected many communities because of its wilderness location.
“It’s a rather remote area,” said Ms Travis. “That’s probably the only good thing about the fire.”