Forest fuels east of the Continental Divide are already drier than a typical August and are driving the rapid growth of a 1,000-acre wildfire in the Bob Marshall Wilderness.
The Elk Hill Fire is still uncontained in the Helena-Lewis and Clark National Forest. It was first reported Saturday morning near the North Fork of the Sun River.
Mike Munoz said that in his 17 years as the district ranger in the forest’s Rocky Mountain District, he has never seen a significant wildland fire start this early.
“It’s April,” Munoz said. “If we’re unable to catch this fire and get it contained, controlled and at least to the point where we don’t think it’s going anywhere, we’ll be living with it way too long. Last year our season extended into early November.”
As of early afternoon Monday, the fire was estimated at 1,086 acres and was burning half a mile from the Forest Service’s administrative cabin along Cabin Creek.
The K-Bar-L Ranch is about 2.5 miles away from the fire front.
On the bright side, Munoz said, the fire likely won’t advance much farther north toward the cabin; last year’s Moose Ridge Fire already burned much of the fuel within 100 yards of the cabin.
The fire is believed to have been started by a campfire or a warming fire, and Munoz noted that many people visit the area this time of year in search of elk antlers. Lightning has been absent from the area for weeks.
Law enforcement officers have begun an investigation and are following up on license plate information gathered from vehicles in the area that day.
The likely manmade nature of the fire, coupled with the unseasonably early start, led Munoz to authorize fire personnel to use chain saws as they work to contain the fire — another first in his time on the job.
Like other mechanical and motorized equipment, chain saws are generally prohibited in federally designated wilderness areas, but there are some exceptions. Twice before, Munoz has allowed chain saws in his district, but only for post-fire cleanup when workers couldn’t safely remove hazardous snags with cross-cut saws.
On Sunday, three helicopters dropped water on the fire, attempting to stop its progress on its southeast and northwest edges.
A total of 24 fire personnel, including eight smokejumpers from Missoula who were flown up Sunday morning, were working for the Type 3 Incident Management Team assigned to the fire.
Munoz said it was initially tough to wrangle up the help needed to combat the fast-spreading fire, which grew from 200 acres late Saturday morning to 500 acres six hours later. It added another 500 acres on Sunday.
“We’re doing a lot better than we thought,” Munoz said. “At first we were sending two to three people in with horses and mules and figured that was all we’ve got. Fortunately we got some helicopters with the capability of delivering large amounts of water, so that’s making a big difference.”
Fire professionals measure the moisture in forest fuels to determine how dry conditions are, providing one indicator of overall fire potential.
Close to where the fire started, Munoz said the heavier fuels measuring 10 inches or more in diameter are so dry that the moisture probes don’t register any humidity.
The probes require at least 8 percent moisture to return a reading. Typically, those fuels won’t dip below 20 percent until mid- to late August, he added.
“The grasses are readily available for spreading rapidly, and at the same time, some of the downed dead fuel is very receptive to ignition.”
It’s the second straight year in which the Sun River drainage has snowpack below 60 percent of normal. High elevation gauges on Monday recorded that figure at 57 percent for the Sun, Teton and Marias river drainages.
On the west side of the Divide, fuel moisture measurements are well above normal for April.
And snowpack levels are healthier on the west side, too.
On Monday, mountain snowpack in the Flathead and Kootenai river drainages was at 88 percent and 90 percent of average, respectively.
Reporter Sam Wilson can be reached at 758-4407 or by email at firstname.lastname@example.org.