More than 2,100 firefighters were once again struggling to contain the vast Bootleg fire raging in southern Oregon near the California border, while some were forced to pull out as the blaze spread in the middle of the fourth intense heat wave of summer.
California, hit by its own wildfires, has vowed to send firefighters to help Oregon.
An initial examination on Friday showed that the Bootleg fire destroyed 67 homes and 117 outhouses overnight in a county, while forcing 2,000 people to evacuate. 5,000 other buildings, including homes and smaller structures in a rural area just north of the California border, are also at risk, said fire spokeswoman Holly Krake.
Active flames are sweeping 200 miles (322 km) from the blaze’s perimeter, she said, and it is expected to merge into a smaller but equally explosive blaze by nightfall.
The Bootleg Fire is now 976 square kilometers (377 square miles) – larger than the land area of New York City – and remains controlled at just seven percent, according to the InciWeb website.
“(The) fire remains very active with a significant increase in area due to the hot, dry and windy conditions,” the official website said.
“We’re probably going to continue to see the growth of fires over miles and miles of active fire line,” Krake said. “We keep adding thousands of acres a day, and it has the potential every day, looking forward to the weekend, to continue those three to four mile runs. “
A red flag weather warning was issued for the area until Saturday evening.
“We had record heat and all the worst possible conditions at the same time,” US Forest Service spokesperson Suzanne Flory told the Oregonian newspaper.
Extreme heat and drought conditions have fueled wildfires across the western United States and Canada in recent weeks – and have pushed firefighting resources to their limits.
Canada is bringing in around 100 firefighters from Mexico to reinforce their exhausted counterparts from northwestern Ontario, provincial officials have said.
Canadian officials are forecasting high temperatures in the coming days from Alberta to Ontario – although nothing resembles the record 121 degrees Fahrenheit (49.6 degrees Celsius) recorded near Vancouver three weeks ago.
This heat wave has contributed to hundreds of deaths in British Columbia alone, authorities said.
Meanwhile, air quality alerts have been issued in four provinces in western Canada.
Scientists say current heatwaves would have been “virtually impossible” without man-made climate change.