Mitigating wildfire risk in Rattlesnake Canyon, Forest Service crews thin, burn hundreds of small trees

TJ Flanagan works to ignite a few of the hundreds of slash piles above the Rattlesnake Canyon. (Laura Lundquist/Missoula Current)

For the past few days, fog has often blurred the mountains above the Rattlesnake Canyon. But looking closer at the eastern slopes, you might see smoke columns mingling among the misty tendrils. They’re an indication that U.S. Forest Service crews are scrambling to do what burning they can to keep the Marshall Woods Restoration Project on track before the winter snows hit.

All this week, a crew of eight Forest Service employees have been tromping the forest north of Woods Gulch, trying to burn hundreds of piles of tree trunks and branches that crews cut and stacked a year or more ago.

“Weather is a major factor. We know it’s getting colder and the snow levels are coming down. Snow can be problematic if it gets to be too wet and too cold to get the piles started. And it’s more of an issue safety-wise in this steep country,” said Forest Service fuels specialist Andy Bidwell.

Slipping through the wet pine needles covering the slopes, fire boss trainee Jake Fallis stopped at one of the carefully stacked piles. Peering in, he searched for the parchment paper placed at the center of each pile to keep parts of the wood dry and to enable ignition.

That’s where he poured the burning fuel from his drip torch and waited a few moments before trying again. Eventually, smoke and a lick of flame showed he’d hit his mark, and he turned toward the next pile.

The crew worked quickly, spending about three or four minutes lighting each pile before moving 10 or so yards to the next. Behind them, smoldering smoke evolved into bonfire flames as the piles burned hotter. The aroma of a campfire replaced that of mud and pinesap.

Fallis stopped occasionally to watch the smoke rising above the treetops. His hope was to continue lighting piles into the early afternoon, but that might not be possible if the weather changed. If the air started to stagnate, he’d have to stop sooner.

So many aspects of controlled burns are balancing acts, Bidwell said, especially when it comes to timing.

Kyle Gard reaches to the center of the slash pile to ignite the driest wood. (Laura Lundquist/Missoula Current)

After the Community Wildfire Protection Plan identified the Marshall Woods area as having the second-highest wildfire risk in Missoula County, crews have been cutting a certain proportion of young trees to reduce that risk.

They stack the cut trees in piles no more than about 3 or 4 feet high, but the wood is too green to burn immediately. It has to cure at least a year, so crews don’t have to waste time convincing them to burn.

But if the piles sit longer than about two years, too much moisture gets in and rot takes over, again making them harder to burn. So Bidwell has a period of about a year to play with.

But that’s where the second balancing act comes in.

For safety, burning is limited to only certain times of the year that are moist, namely spring and fall. But even at the right time of year, all the conditions have to be just right: The temperature has to be cool but not too cool, and it can be wet but not too wet.

That really narrows Bidwell’s window of opportunity this year to try to burn about 150 acres worth of woodpiles. That’s about the amount of wood the Forest Service burned on the project last year.

The problem is that when it’s good for Bidwell to burn, it’s a good time for everyone to burn. But if all the agencies and private landowners burned at the same time, the smoke in the valley and perhaps across the state would be a lot more oppressive.

Forest Service fuels specialist Andy Bidwell and fire boss trainee Jake Fallis consult to ensure all burning conditions are perfect before igniting burn piles in the Rattlesnake Canyon earlier this week. (Laura Lundquist/Missoula Current)

That’s where the Montana-Idaho Airshed Group comes in. Created in 1978, the Airshed Group – made up of representatives from the forest products industry and federal, state and local agencies – manages the daily impacts of smoke generated in the two-state area from prescribed burning to meet the requirements of the Clean Air Act.

“It coordinates who is putting how much smoke into the airshed,” Bidwell said.

Bidwell has to submit his burn proposal every day along with other burn coordinators. The Airshed Group totals how much smoke all the proposals might produce and approves only the amount of burning that the weather conditions can support. Missoula County also gets involved because of the local tendency toward inversions that trap smoke in the Missoula Valley.

Low pressure systems help disperse smoke better, so the Airshed Group can approve more projects when low systems are in the area.

For much of this week, that’s been the case, so it’s been full-speed ahead for Fallis’ team. But that wasn’t so a few weeks ago.

Rain had moved in and the team started working. But a few days later, the long-term forecast changed, showing a warm spell was coming. The crew stopped because they didn’t want fires to still be smoldering as temperatures climbed.

“We wouldn’t want to push it up to the edge. We know there will be a few days of lingering smoke that we don’t want to contribute to stagnant air,” Bidwell said.

To make up for the delay, the crews need to burn as many piles as possible. If they can’t get to some in time, the piles may end up as habitat for wildlife.

“I think we’ll be in a good spot. It’s a constant tradeoff, and we’d love to go and go and go. But if we don’t have the people or conditions to do that, we’ll just be patient,” Bidwell said.

Contact reporter Laura Lundquist at lundquist@missoulacurrent.com.