Montana fire spreading quickly

BOISE, Idaho (CNN) -- Fire officials on Friday are focusing on a fire that scorched more than 15,000 acres in Montana in less than 24 hours.

Twenty-six large fires continued to burn in eight states -- California, Idaho, Montana, Nevada, Oregon, Utah, Washington, and Wyoming -- as some 23,000 firefighters and officials worked to reduce that number.

More than 100 new fires were reported to National Interagency Fire Center in the previous 24 hours, but only three of those grew into large fires, said Rob Kopack, a fire information officer with the Boise, Idaho-based NIFC.

"Anything under 200 is good," Kopack said. "We get on them quick while they're small and they won't grow big."

Cooler temperatures moved into Oregon and Washington, while high winds, hotter temperatures and lower humidities arrived in California and Montana -- states fire officials are most concerned about.

The Fridley Fire, in Montana's Gallatin National Forest near Bozeman, gained strength Thursday when dry vegetation and heavy winds spread the blaze to nearly 12 miles long, said Fridley fire information officer Bobby Kitchens. Firefighters were brought in after conditions became so dangerous that the blaze became a threat to the helicopters that were dropping water.

So far, firefighters have not been able to contain any of the blaze, which could be seen from miles away.

An estimated 500 structures -- mostly homes -- are near the fire, which has scorched some 20,000 acres since it began Sunday. The fire had covered only 4,000 acres before Thursday morning.

"We do not expect that type of spread today," Kitchens said. "The weather is more favorable and the ... direction the fire is going, it's getting down in a valley where fuels are not so heavy."

Kitchens said most of the nearby homes are "defensible," that is, there are clearings around the houses.

The NIFC is also keeping an eye on four large fires burning in California, although all are more than 50 percent contained.

"The California fires aren't a huge concern in and of themselves," said Davida Carnahan, an NIFC fire information officer.