Firefighters in Yellowstone National Park focused their attention once again on an area near Old Faithful geyser on Saturday, and a fast-moving forest fire in Idaho killed a flock of sheep and their accompanying sheep dogs.

Oregon activated 100 National Guardsmen and borrowed firefighters from Canada to help battle out-of-control blazes."We're hanging on by our fingernails," said Lee Oman, incident commander at a firefighters' base camp in Valley of the Rogue State Park near Grants Pass, Ore., where crews battled two blazes that threatened homes in rural areas.

Forest also burned in parts of northern California and Washington state.

Officials in Yellowstone appealed Saturday for private helicopters and crews to help fight the blazes that have charred more than 400,000 acres of the park. About 35 helicopters have been working on the Yellowstone complex of fires in Yellowstone and Grand Teton parks and the adjoining Bridger-Teton, Shoshone and Targhee national forests.

Dave Poncin, a firefighting commander in Wyoming, said he would like to have another 15 to 20 helicopters.

"Military pilots are good, but they're not bush pilots. What we need are oilfield pilots, people who fly in the mountains a lot and are familiar with this kind of terrain," he said at a news briefing. "We're looking of course for the best in the business, and they're probably not available. So that's where we're at."

A shift in wind direction in Yellowstone created a 250-acre spot-fire about five miles from Old Faithful, the park's most popular attraction, where nearby structures earlier were threatened by flames.

Linda Miller, a fire information officer, said the fire was created when wind fanned flames on the southern end of the 114,000-acre North Fork fire.

Crews worked to build a containment line around the blaze by hand and were aided by an air tanker, and the buildings around the geyser were not threatened Saturday, morning, Miller said.

In eastern Idaho, wind pushed a forest fire over an extra 1,200 acres to a total 3,500 acres and killed an undetermined number of sheep, Caribou National Forest spokesman Dan Pugmire said Saturday.

"The fire just made an end run on us yesterday afternoon," Pugmire said.

The sheepherder escaped injury, but his sheep dogs also were destroyed by the advancing Trail Creek fire, he said.

Near Idaho's border with Oregon, the Eagle Bar fire near Hells Canyon continued to rage. It trapped 30 firefighters Friday and forced them to spend an hour in portable shelters called fire deflectors. They were not injured.

Fire information officer Jeanne Felmy said the fire had burned 3,450 acres by Saturday, up about 450 acres Friday.

In south-central Montana, just north of Yellowstone, the Storm Creek fire grew by 2,000 acres overnight to 37,500 after shifting wind pushed the flames west rather than south into the towns of Cooke City and Silver Gate.

About 12 miles west of Storm Creek, the Hellroaring Creek fire grew to 33,000 acres and was "heading very close to" Yellowstone, spokeswoman Stephanie Gibert said Saturday.

In northeastern Oregon, the 7,700-acre Troy-Ward Canyon fire remained a threat to the tiny outpost of Troy, but none of the 14 residents had been evacuated.

Evacuation plans also were on hold for the 1,000 residents of a subdivision north of Grants Pass and about a half mile from the 1,550-acre Walker Mountain fire. The fire still threatened homes but was moving away, said Mike Barsotti, a state Forestry Department spokesman.

Firefighters subdued a blaze that burned more than 1,800 acres of trees and grass and forced the temporary evacuation of eight families south of Cloverdale, Calif., 65 miles north of San Francisco.