Associated Press

PORTLAND, Ore. — The threat of thunderstorms and lightning has prompted officials in fire-ravaged Oregon to ask for help from outside the Pacific Northwest to prepare for additional blazes as many resources are already devoted to a massive forest fire.

The 569-square-mile Bootleg Fire is burning 300 miles southeast of Portland in and around the Fremont-Winema National Forest, a vast expanse of old-growth forest, lakes and wildlife refuges. Evacuations and property losses have been minimal compared with much smaller blazes in densely populated areas of California.

But eyeing how the Bootleg Fire — fueled by extreme weather — keeps growing by miles each day, officials with the Rogue River-Siskiyou National Forest in southwest Oregon are asking for more outside crews to be ready should there be a surge in fire activity there.

“Although the lightning activity predicted for early this week is expected to occur east of us, we are prepared for the worst, and hoping for the best,” Mike McCann, an assistant fire staff, said Monday in a statement released by the national forest.

The worry is that dry conditions, a drought and the recent record-breaking heat wave in the region have created tinderbox conditions, so resources like fire engines are being recruited from places like Arkansas, Nevada and Alaska.

Meanwhile, to the east, the Bootleg Fire’s jaw-dropping size contrasted with its relatively small impact on people underscores the vastness of the American West and offers a reminder that Oregon, which is larger than Britain, is still a largely rural state, despite being known mostly for its largest city, Portland.

If the fire were in densely populated parts of California, “it would have destroyed thousands of homes by now,” said James Johnston, a researcher with Oregon State University’s College of Forestry who studies historical wildfires. “But it is burning in one of the more remote areas of the lower 48 states. It’s not the Bay Area out there.”

At least 2,000 homes have been evacuated at some point during the fire and another 5,000 threatened. At least 70 homes and more than 100 outbuildings have gone up in flames.

Thick smoke chokes the area where residents and wildlife alike have already been dealing with months of drought and extreme heat. No one has died.