ALBERTON, Mont. (AP) -- Ten houses in a drainage south of here remained under evacuation orders Sunday, as more crews arrived to help protect those and other structures threatened by a growing complex of fires started along Interstate 90.
More than 500 firefighters struggled against hot, dry weather and high winds Sunday to keep the human-caused fires at bay. One of the blazes had crept closer to the homes overnight, but none had been lost, fire spokeswoman Elsha Kirby said.
Several commercial structures and power lines also were threatened.
''The crews are doing structure protection,'' Kirby said. ''They've been doing it all night, all through the night and they are continuing to do so today.''
The fires, sparked Thursday along Interstate 90 in western Montana, had burned about 4,000 acres as of Sunday evening, the equivalent of 6 square miles, and were 10 percent contained. Authorities did not know how many people were evacuated, but said several residents had chosen to stay with their homes.
A 90-mile stretch of I-90 had been closed by the fires Friday. Although all but one lane was reopened by Sunday, authorities were considering closing the highway again because of accidents, Kirby said.
At least one firefighter had witnessed a rollover crash in the area, she said. Drivers had been told to expect reduced speeds, smoke, firefighting equipment and even wildlife along the roadway, but many still aren't paying attention, Kirby said.
''We're worried not just about firefighter safety, but about the public driving along and rubbernecking,'' she said.
Authorities were considering another highway closure, or further reducing speeds.
Investigators, meanwhile, were still trying to determine the cause of the fires. Half a dozen or so law enforcement officers had combed the edges of I-90, looking for clues, and had asked the public for help.
Elsewhere, the lighting-caused Prospect fire had quickly burned 350 acres in the Lolo National Forest near St. Regis and was spotting a mile ahead of the main blaze.
In the Bitterroot National Forest to the south, the Rock Creek fire complex grew on Sunday to about 2,500 acres. Control efforts included helicopter water drops, although a Type II management team was expected to take over on Monday, forest spokeswoman Christine Romero said.
The Kelly Point fire, discovered Saturday near Black Bear Cabin in the Bob Marshall Wilderness, was believed to be human caused and had grown to an estimated 500 acres, Flathead National Forest spokeswoman Denise Germann said.
The blaze jumped the South Fork Flathead River and was spreading east up Hodag Creek drainage. Crews were working to protect the Black Bear Cabin, a Forest Service facility used as a summer work center.
The lightning-caused Limestone Peak fire ballooned to about 100 acres Sunday from just 10 acres the day before. It was burning in a remote area of the wilderness area, Germann said.
Copyright 2005 Associated Press