SUMMIT COUNTY — The men stomp through the snow, snaking torches into stacks of timber and sparking flames.
Soon, thin wisps of smoke turn dense and dark as orange flames lick the 10-foot tall piles of dead trees. Dozens of bonfires begin melting growing rings of snow, sending smoke high above Summit County last week.
Flames soar in between Aspen trees for prescribed pile burning of pine beetle-killed trees in Frisco. (Hugh Carey, The Colorado Sun)
The Forest Service has planned this slash-pile inferno for years, part of its expansive plan to rid the woods of the invasive pine beetle. Since 1996, the ravaging beetle has killed 3.4 million acres of lodgepole and ponderosa forest across Colorado. Forest Service fuel planners have scraped entire mountainsides of the dead timber, neatly stacking the trees as they wait for the right moment to reduce the beetle devastation to ash.
In Summit County, those Forest Service officials burn about 400 acres of slash piles a year.
“A challenge with much of the timber resources in Colorado is that it is not commercially viable for logging operations,” said David Boyd, a public affairs officer with the Forest Service. “We are working closely with the state of Colorado, Summit County and other partners to reduce the amount of fuel and dead trees in Summit County.”
In a gulch just beyond the slopes of the Keystone ski area, many of the standing trees are dead. Forest Service crews spent last summer cutting down the brittle trees and stacking them in tidy piles. Then they waited, gauging not just the right wind, air, temperature and snow conditions, but also when the wood itself was dry enough to burn quickly and efficiently. Forest Service crews keep an eye on the sky when it’s time to burn slash piles. They want snow on the ground, but not any forecast to fall, which can dampen the burn.
MORE: Monarch Pass could serve as a new model for wildfire mitigation in treacherous areas
“The perfect condition is some standing snow around piles and, you know, good to excellent ventilation rates,” said Dusty Calfee, an engine captain with the Forest Service’s Dillon Ranger District. They aimed for the smoke to rise out of the burning piles and disperse high above, limiting the impact on air quality in the valley floors.
“The general conditions of the fuels around the pile so if we’ve had enough moisture recently that we’re not concerned about fire creeping out from the piles along the surface of the ground and looking at weather so if atmospheric conditions are right for good ventilation.”
The forest thinning reduces the chances of uncontrollable wildfire reaching homes and structures and it opens terrain for firefighters to more easily move through the rugged terrain. Dead trees lying on the ground – known as “jackstraw” – can turn forests into obstacle courses for firefighters.
“When firefighters have to engage in those areas where that timber has fallen down on itself … it’s really difficult country to hike through,” Calfee said. “It’s difficult to navigate it, and it puts off an incredible amount of heat when you have to fight fire in those areas.”
The fuel planners last week wiggled out of their harnesses and heavy gear on the steep hillside of Keystone Gulch for a lunch break, keeping watch over the smoldering piles surrounded by healthy ponderosa, lodgepole pine trees, aspens and homes. Those burning piles give them a better chance of weathering the upcoming wildfire season with less fuel to ignite an inferno.