Largest fire in U.S. burns in Oregon

Motorists traveling on U.S. Highway 199 navigate through smoke from the nearby Florence fire near Cave Junction, Oregon.

CAVE JUNCTION, Oregon (CNN) -- Fire crews in southwest Oregon on Sunday were able to keep the largest wildfire in the United States from forcing the evacuation of thousands of Illinois Valley residents.

"Burnouts done yesterday and today have been successful in securing the line," said Mark Hollen, a fire information official. "And we've been able to raise the evacuation notice time from 30 minutes to two hours."

Hollen said the Florence fire -- just outside of Cave Junction -- has burned over 198,000 acres.

The Florence fire is the biggest in the nation and is the largest of others in the state by far, he said.

"They're saying it's 5 percent contained, but that's whistling in the dark ... when you have a fire that's almost 200,000 acres and doing its own thing," Hollen said.

In addition to the Florence fire, the 2,000 firefighters in the state are battling the 40,000-acre Sour Biscuit fire, the Timbered Rock blaze that has burned 25,000 acres, and the 30,000-acre Tiller Complex fire, Hollen said.

Crews have made progress in containing other fires, he said.

Firefighter Jose Martinez from Ontario, Oregon, works on a stump as crews mop up a burnout area of the Florence Fire near Selma.

"The number of fires has dropped considerably. Besides the four I've just mentioned, there are three other fires which, if not fully contained, are in 90 percent containment," Hollen said.

Five type-1 "hotshot" crews from Canada will arrive in the next day or so, he said, and help of another kind also may be on the way.

"Right now, a cool, moist Pacific front is coming in that may give us some moisture [and] give the fire folks a little break," he said.

But, Hollen said, the expected weather change could prove to be too much of a good thing and hinder firefighters' efforts to hold the lines.

"In the burnouts, if the humidity's too high, the underbrush won't catch fire. And, [the weather] could cause trouble with thunderstorms and winds," he said.