MISSOULA, Mont. (AP) -- The Tarkio wildfire burning west of here along the Interstate 90 corridor is kicking up and firefighters may not be able to keep up with it, a fire official says.
''We're in a very active firefight as we speak,'' fire boss Bob Sandman told area residents Tuesday night.
''We're throwing everything we have at it. I'd hate to venture at how big this fire will get,'' said Sandman, incident commander on the I-90 fires. He said the latest breakout by the Tarkio fire might outrun efforts to stop it.
The Tarkio fire, named after a nearby community, and the West Mountain fire, northwest of Alberton, are known at the I-90 fires, and both potentially threaten a major Bonneville Power Administration transmission line that supplies electricity to the Pacific Northwest. Fire officials said an air tanker has been assigned to help protect the transmission line.
Combined, the fires total about 4,300 acres are considered the nation's No. 2 priority, behind a wildfire burning in Washington state. Officials said about 850 people are on the lines.
''This is a high priority fire because of the BPA power lines. We have contingency plans to protect that,'' said fire information officer Pat McKelvey. ''Part of the contingency plan would be that if the fire would make a run toward the power line, the retardant would be used to slow the fire growth.''
High winds pushed the Tarkio fire Tuesday afternoon, and Sandman said it had the potential to run a mile or more over a 24-hour period. ''We knew that once the fire jumped Nemote Creek that we were in a horse race, and it turned out that our horses weren't that fast.''
The fire jumped fire lines dozed in front of it as if they weren't there, he said.
Westbound traffic on I-90 remained restricted to one-lane through the fire area, but part of a 20-mile portion of the Clark Fork River was reopened to boat traffic. Helicopters are using the river to fill water buckets.
Another fire in western Montana, the Prospect fire, was estimated at 1,000 acres Tuesday, burning in remote, difficult terrain near the I-90 corridor, not far from Superior, with about 240 people assigned to fight it.
''It's a messy fire,'' said fire safety officer Jim Bartlett. ''We've got limited access, very steep slopes and ratty edges, but will continue to be persistent.''
The Prospect fire was started by lightning, while the other two fires were human-caused, officials said.
Several other fires were burning in western and northwestern Montana, but none showed significant growth Tuesday. Several additional lightning-caused fires also were reported throughout the region.
The Camp 32 fire in the Eureka area of northwestern Montana has burned about 900 acres since starting Sunday afternoon on the northeast end of Lake Koocanusa. It's encircled but burning vigorously within fire lines, officials said.
Firefighters are sleeping and showering at the school in Eureka, and are being transported to the fire camp in school buses, said Gary Blaz, superintendent of the Lincoln County School District.
In the Bitterroot Valley south of Missoula, officials said higher humidity and some rain tempered fires, but updated mapping showed the Rockin Complex of fires in a wilderness area west of Darby at about 4,300 acres.
A special team of firefighters from Helena was working along the Rock Creek Trail west of Lake Como to keep the fire from crossing the Rock Creek drainage to the south, said officials of the Bitterroot National Forest.
On the Flathead National Forest, three fires were burning in the Bob Marshall Wilderness Complex, including the 3,200-acre Kelly Point fire near the South Fork of the Flathead River.
Copyright 2005 Associated Press