EVERGREEN — Trunks and logs lie askew, fresh-cut stumps dot the landscape and dozens of piles of ponderosa branches, browned and desiccated, sit on the forest floor at Alderfer/Three Sisters park in the Jefferson County foothills.
To Ruthe Hannigan, a 31-year Evergreen resident walking through the park on a chilly October morning, the sight of so many downed trees and exposed stumps is tantamount to “a great combination of awfulness.”
“They’re not doing fire mitigation, they’re selling it as fire mitigation,” said Hannigan, 75. “We’ve been meeting people on the trails and they are furious about it. I try not to walk this trail anymore — it’s so depressing.”
Her husband, 76-year-old Darrell Luebbe, said Jefferson County’s effort to thin the forest on its high-elevation open space properties is leaving behind a giant mess. He barely recognizes the park these days, with landmark trees cut and gone, and new vistas unveiled that weren’t there before.
“This used to be all trees,” Luebbe said, gesturing into the distance. “I understand the need for wildfire mitigation, but you don’t need to take down this many trees.”
Wildfire mitigation is a hot topic in Colorado, with the fire season now stretching well beyond the sweltering summer months as the climate warms and a megadrought continues to dry out the American West. The 20 largest wildfires in the state’s recorded history have all occurred in the past 22 years, burning nearly 1.5 million acres or more than 2,300 square miles — the equivalent of burning Rocky Mountain National Park roughly six times over.
And there is disagreement on how best to keep flames under control and away from neighborhoods. Luebbe, a cancer survivor, hikes in Jefferson County’s vast open space properties as part of his therapy — for both physical and psychological betterment. Denuding sections of the forest via thinning operations leaves him dismayed.
“It’s just devastating,” he said. “It’s so sad to see what was a beautiful park. It’s been ravaged. There has to be a better way.”
Chad Julian, wildfire mitigation program specialist for the Colorado State Forest Service, said tree thinning is a common forest management practice in the state. The purpose of taking out some trees and reducing the density of the forest, he said, is to “manage vegetation to alter fire behavior.”
“It’s ecologically appropriate to be doing it in ponderosa pine, Douglas fir and mixed conifer forests because those forests were so open for thousands of years,” Julian said. “We are trying to get the forests back into balance to where they were for 9,000 years. If we don’t get in there with thinning, we can’t change those fuel conditions.”
Steve Murdock, natural resources supervisor for Jefferson County, acknowledges that felling trees creates an unsightly slash zone — but only in the immediate term. Given time, the newly sun-splashed ground will sprout new growth and the next generation of saplings and forest understory will take hold, he said.
More importantly, leaving the woods as is, he said, is a recipe for a wildfire disaster in an area chock full of homes, schools and businesses — a zone referred to as the wildland-urban interface. With fire suppression as the chief land management tool over the past century, Colorado’s woods have grown denser and become choked with tinder-dry fuels.
“What we don’t want to see is a closed ponderosa forest canopy,” Murdock said. “Thinning forests to promote eco-resilience is the best thing we can do to mitigate against those wind-driven fires.”
The county in the last four years has treated nearly 900 acres of its 25,000 acres of forested open space property, with plans to hit another 1,500 acres by 2030. Besides Alderfer/Three Sisters, trees have also been removed at Jefferson County’s Elk Meadow, Flying J Ranch and Meyer Ranch parks.
“What we’re trying to prevent is that high-intensity, large-scale crown fire,” Murdock said.
Community condemnation
Jefferson County’s open space department ramped up its forest management efforts on its foothills properties in 2020, the year Colorado was walloped by its three largest wildfires on record. Opposition to the department’s tactics has only grown as more trees have come down.
In October, dozens of foothills residents crowded into the Evergreen library to demand a change to the way Jefferson County approaches the challenge of reducing fire risk. Toppling trees, several attendees said, has negative impacts on wildlife and water quality. And removing sections of the forest canopy, they said, allows the sun to heat up and dry out the understory, making the forest more susceptible to burning.
Clearing out trees also makes wind tunnels that can create blowdowns of standing trees while helping spread flames more rapidly should a fire occur, said Josh Schlossberg, Colorado organizer for the national environmental advocacy group Eco-Integrity Alliance, who has been active in calling attention to the issue.
“And it’s that wind that’s going to blow the fire toward communities,” he told The Denver Post during a two-hour trek through a section of the 11,300-acre Alderfer/Three Sisters park in October.
One notable critic of the county’s approach is state Rep. Tammy Story, who has lived in Jefferson County’s foothills for nearly 40 years and represents the area in the statehouse. At the October community meeting, she said Jefferson County’s mountain parks “are being devastated.”
“That the action being taken is not to the benefit of the forest, it’s not to the benefit of the wildlife, it’s not to the benefit of our water resources and that it’s highly detrimental,” she said.
But at the county level, Commissioner Lesley Dahlkemper said Jefferson County is following the science in carrying out its wildfire mitigation efforts. Much of its analysis and methodology on the topic is laid out in a 92-page Forest Health Plan, published in 2022.
“While the treatment at first can look jarring, it will open up the forest floor,” Dahlkemper said. “The long-term impact is a healthier forest.”
But Schlossberg said concern over wildfires in Colorado — brought into terrifying relief by the Marshall fire’s dramatic incineration of more than 1,000 homes across southern Boulder County nearly three years ago — has led to a simmering panic among wildland managers when it comes to fire management.
On a steep grade off-trail at Alderfer/Three Sisters, Schlossberg pointed to dozens of stacks of ponderosa logs and branches — the result of previous cuts. That quickly drying detritus, he said, exacerbates the fire danger.
“This whole damn forest is slash piles,” he said.
Tree-felling deep inside a park or open space property does little to protect homes off in the distance, he said. It’s better to harden homes and create defensible space around houses to protect them from fire, he said.
“The logging here heats up the forest microclimate,” Schlossberg said. “Heating up the forest is what is going to cause crown fires.”
Dueling wildfire studies
In some ways, the dispute over forest management practices in Jefferson County has devolved into a war of dueling scientific studies, with each side pointing to research that buttresses its position.
Jennifer Balch, associate professor of geography at the University of Colorado Boulder, understands why Jefferson County is taking out trees in its ponderosa and mixed-conifer forests.
Balch, who recently authored a study on fast-moving wildfires over the last two decades, said one of the primary worries of fire managers is keeping flames out of the treetops — known as crown fires, which burn hotter and are harder to fight.
“It’s way easier for firefighters to be fighting a ground fire than a crown fire,” she said. “You don’t want ponderosa pine torches that are 30 to 40 feet high.”
Kimberley Davis, research ecologist at the Missoula Fire Sciences Laboratory, was part of a study published this fall that examined 40 case studies where wildfire was present in treated areas.
Her analysis found that through forest thinning alone, average fire severity was reduced by 27% compared to untreated areas. That severity reduction leaped to 72% when thinning was followed by prescribed burning — the practice by which land managers deliberately set fires to eliminate fuel loads in a forest.
“By thinning, you reduce the fuels in the canopy and you make it more difficult for a canopy fire to spread,” Davis told The Post in an interview.
One caveat in Davis’s research is that, in some cases, “thinning treatments led to higher wildfire severity than in nearby untreated areas, likely due to increased surface fuels left from thinning activities.”
“These findings underscore the importance of treating surface fuels through burning when reducing future wildfire severity is the goal,” the study found.
But Jefferson County’s open space department hasn’t conducted a prescribed burn in 12 years, following the disastrous 2012 Lower North Fork fire that started as a controlled burn by the Colorado State Forest Service before escaping containment lines. The fire, which occurred in the southwest part of the county, destroyed 27 homes and killed three people.
Murdock, the natural resources supervisor for Jefferson County, said prescribed burns are critical to restoring ecological health to the county’s forests. The county’s open space department is “working towards restarting our burn program and hope to have that going again in the very near future.”
Dominick DellaSala, chief scientist with Berkeley, California-based Wild Heritage, said thinning works in “very limited” situations. In general, he urges land managers to “keep carbon in the forest” by leaving older and larger trees in place.
“If you take too much material out of the forest, you’re overventilating it and drying it out,” he said in an interview.
DellaSala is one of more than 200 scientists to sign a 2021 letter to President Joe Biden and members of Congress outlining some of the problems with forest thinning.
“We have watched as one large wildfire after another has swept through tens of thousands of acres where commercial thinning had previously occurred due to extreme fire weather driven by climate change,” the letter reads. “Removing trees can alter a forest’s microclimate, and can often increase fire intensity.”
The main spurs for Colorado’s wildfires, DellaSala told The Post, are extreme temperature, drought and high winds.
“Fuels are secondary,” he said.
“The forest is gone”
Dahlkemper, the Jefferson County commissioner, said her job is bridging the science and the concerns of her constituents. She said she’s been up to the county’s foothills parks to see the problem herself.
“The county has to balance best practices in forest management with community feedback that is raised,” she said. “And then how do we fit together all the pieces of the puzzle?”
Murdock said the open space department has made changes to its protocols in response to residents’ concerns. In Elk Meadow Park, trees were left in place along trails to provide more shade and less thinning was done in the interior of the park.
And with 2,500 acres treated across 25,000 acres of forested county-owned land by the end of the decade, the impacts are limited, Murdock said.
But the payoff is big, he said.
“We’re only taking about 10% of our park system, but that will reduce the risk of catastrophic wildfire by 30%,” he said.
Hannigan, the longtime Evergreen resident, said she will continue to fight the county’s approach to wildfire mitigation. With the three rock outcroppings that give Alderfer/Three Sisters park its name jutting into the blue sky behind her, she said enough damage has been done.
“I don’t recognize it. The forest is gone,” she said.
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