A wildfire burning about seven miles southeast of Swan Lake has grown to 450 acres, even with diminished activity because of a cool weather front that moved into the area Monday.

The front delivered wind gusts of 20 to 30 mph, stirring up the South Fork Lost Creek Fire at times, but there also was a trace of precipitation during the day.

The fire is believed to be caused by people, starting near the South Lost Creek forest road and then burning uphill into steep, heavily timbered terrain. The fire first was detected Saturday afternoon.

“It’s extremely steep and difficult and at this point it’s not safe to put anybody at the top of the fire,” said Jeremy Pris, deputy incident commander with the Montana Department of Natural Resources and Conservation.

One firefighter suffered a dislocated shoulder Monday and required ambulance transport.

About 150 people are working on the fire, with a main strategy of anchoring fire line at the south “heel” of the fire and then extending line from there.

There were six helicopters working on that fire and another one burning farther north on the west slope of the Swan Mountain Range near Peters Ridge.

That fire is estimated to cover 10 to 20 acres and also is burning in steep terrain that is difficult to reach.

“Yesterday, we jumped a load of eight smokejumpers on Peters Ridge,” said Steve Frye with the state’s Northwest Land Office in Kalispell. That fire also is staffed with two Hotshot crews and a Type II initial attack crew.

One smokejumper suffered a dislocated hip and had to be airlifted from the Peters Ridge Fire on Sunday.

Both the Peters Ridge and South Fork Lost Creek fires are visible from the Flathead Valley.

Meanwhile, the Hammer Creek Fire continues to be active in the Bob Marshall Wilderness about 40 miles south of Spotted Bear. It was sized up at 145 acres Monday afternoon.

The lightning-caused fire is being allowed to burn for resource purposes within the wilderness, but it is being monitored to ensure it does not threaten access and trails in the South Fork Flathead River drainage. However, Trail 80 has been closed north of the Big Prairie Ranger Station.

The South Fork Lost Creek Fire has prompted the closure of the Alpine 7 Trail from Inspiration Pass to the junction with trails 396, 86 and 108.

According to Frye, fire and fuel conditions are very familiar for Northwest Montana at this time of year.

“We have been experiencing fire behavior that is typical for August ... despite the heavy snows of last winter and late spring,” Frye said. “The bottom line is it’s typical for our late August fuel conditions.”

Reporter Jim Mann may be reached at 758-4407 or by email at jmann@dailyinterlake.com.