BILLINGS — Two fast-moving wildfires triggered new evacuations in southeastern Montana on Monday as firefighters battled a potent combination of lightning strikes, dry weather and flame-whipping winds.
The Horse Creek fire south of Hysham quickly grew from 3 to 9 square miles overnight. It was the largest of more than a dozen new fires sparked by weekend lightning strikes.
Most were quickly contained, but residents along the Horse Creek and Sarpy Creek basins in Treasure County were evacuated, said Paula Short with the state Department of Natural Resources and Conservation.
A natural gas pipeline and a transmission line that pass through the remote, hilly area also were threatened by the blaze, officials said. Short said the area where the fire is advancing is sparsely populated.
To the southeast, the 290-square mile Ash Creek fire jumped Highway 212 west of Broadus early Monday. The Powder River County Sheriff's Office was evacuating Sonnette and Ten Mile Creek roads.
A brief period of cooler weather Monday was expected give way by Tuesday to a return of hotter and drier conditions.
With the Fourth of July approaching, a special federal fire prevention team arrived in Montana as part of a stepped-up effort to keep man-made fires from adding to the danger.
"It's so volatile out there. If there are winds, the fires can quickly get out of hand," said Melodie Lloyd with the Bureau of Land Management. "We always this time of year beat people over the head with 'Be careful. Be careful.' We really mean it this year."
Gov. Brian Schweitzer said he would not impose a state-wide ban on fireworks, saying such a decision should be left to local officials. About a dozen counties have banned fireworks — but people have still been observed lighting them, state Forester Bob Harrington said during a Monday briefing with the governor.
"It so far doesn't seem to be making a difference, there are folks still shooting fireworks in the evenings," Harrington said.
The governor also reminded tourists Montana is still open for business. He pointed out Glacier is very wet, and trails and camp spots are open everywhere — but said campfires and barbecues are a bad idea.
There were 12 large fires of 500 acres or more burning across Montana on Monday, with more than 1,800 personnel involved in fighting the blazes.
So far in 2012, 335 homes, outbuildings and other structures have been destroyed. Most of those came during the Dahl fire south of Roundup, where 73 homes burned.
About half the fires this year have been human-caused, with lightning strikes responsible for most of the remainder. And conditions are considered prime for the fires to continue. Schweitzer said such high fire potential is usually not seen until the height of summer in August.
The largest fire is the still-growing Ash Creek fire, which is burning on and to the east of the Northern Cheyenne Indian Reservation.
The fire was reported at 40 percent contained Monday morning, with 16 residences and 22 outbuildings burned so far.
Because the forward edge of the blaze was burning quickly through thick, largely inaccessible timber, firefighters were staying out of its path. Instead, they were concentrating on trying to contain the fire along the edges, said Ash Creek fire spokeswoman Kathy Bushnell.
Another fire that ignited in recent days, the 3,100-acre Bad Horse fire east of Crow Agency, was 60 percent contained by Monday morning.
In Musselshell County, authorities say the perimeter lines around the 22,000-acre Dahl fire held overnight despite heavy wind and thunderstorms. That fire has burned 73 structures and 150 outbuildings, and was 75 percent contained.
A voluntary evacuation order for the Dahl fire was lifted Monday morning.
Bushnell said members of the federal firefighting team brought in to get control of the Dahl fire would be transferred to Colstrip on Monday to help with the Ash Creek and Horse Creek fires.
Matt Gouras contributed from Helena.