Oregon's Bootleg Fire burns more than 150,000 acres and is zero percent contained

The Bootleg Fire in southern Oregon nearly doubled in size from Saturday to Sunday, to more than 150,000 acres, as extreme heat waves and wildfires continued to scorch the West.

The intense flames in Fremont-Winema National Forest, which broke out Tuesday, burned for the sixth day Sunday, according to an incident report. The out-of-control wildfire was so intense that firefighters retreated to safety zones and deployed more personnel overnight, fire officials said.

Residents in some areas of Klamath County evacuated as the wildfire, which was zero percent contained Sunday, continued to spread, the incident report said. Investigators have not determined the cause of the fire; authorities said "dry weather and extremely dry fuels contribute to extreme fire behavior."

The fire interrupted electrical lines that transmit power from Oregon to California, energy officials said. California lost thousands of megawatts of imported power and struggled to maintain operating reserves as temperatures soared into triple digits in parts of the state.

Record wildfires and temperatures are ravaging states across the West.

The Beckwourth Complex Fire — California's largest burning wildfire — consumed more than 80,000 acres and destroyed about 20 homes Sunday as it jumped across state borders to Nevada.

The wildfire, one of several brush fires burning in California, was 8 percent contained Sunday. Federal fire officials reported some progress in holding the fire on the south and southwestern flanks.

"Climate change is considered a key driver" of the state's recent wildfire woes, the California Department of Forestry and Fire Protection said this year.

In Arizona, two firefighters were killed in a plane crash while conducting aerial reconnaissance over the Cedar Basin Fire near Prescott National Forest, the Bureau of Land Management said in a statement.

Wildfires also blazed through western Idaho and southeast Washington over the weekend, prompting Idaho Gov. Brad Little and Washington Gov. Jay Inslee to declare emergencies.