Crews torched brush and other potential fuel Thursday to try to keep two major wildfires from advancing toward homes in a southwestern Oregon valley.

Nearly 1,000 of the valley's 17,000 residents have left their homes since Sunday, but Bob Bell said he was staying put.

"I've got a pond in back that's 7 feet deep, and I'm going to jump in it" if the fire comes, Bell said, using a fire hose to douse the grass beside his house.

Nearly 13,000 firefighters were battling wildfires burning on more than 438,610 acres in the state Thursday.

Top priority was given to two blazes burning across 186,000 acres in the Siskiyou National Forest. The Florence and Sour Biscuit fires were burning less than two miles apart.

Firefighters planned to burn along a 30-mile line to keep the blazes from spreading to several small towns. They've also deemed 90 percent of 300 homes in the area to be defensible against flames.

"Pretty much, our work is done and we are waiting to see if the fire is going to come," said Tim Birr, spokesman for the Oregon state fire marshal's office.

Meanwhile, a fire about 20 miles north of Medford had burned about 20,000 acres and was 20 percent contained Thursday. Officials had urged residents of 40 nearby homes to evacuate.

Elsewhere in the West:

--More than 2,000 firefighters struggled to contain a 17,500-acre blaze in San Diego County that has closed major highways into Julian, Calif. The blaze is expected to be contained by Sunday. Another wildfire raging in the Sequoia National Forest grew to 92,500 acres Thursday. Officials estimated containment at 40 percent.

--Archaeologists accompanying firefighters battling a 3,300-acre fire at Mesa Verde National Park in Colorado found remnants of dwellings used by the Anasazi Indians a thousand years ago. Two tankers dropped retardant on the fire Thursday but it was only 5 percent contained.