Aspen Volunteers Treat 5,000 Trees with Pheromone Patches

The air on the backside of Ajax Mountain feels different this spring. It’s not just the altitude or the thinning oxygen. It’s the silence. Where there used to be the rustle of needles and the chatter of squirrels, there is now a stillness that feels less like peace and more like a held breath. The Douglas-firs are still standing, still green, but they are dead. They are zombies, waiting for the final blow from bark beetles that have gone rogue.

Aspen is mobilizing to fight back, and the weapon of choice isn’t a chainsaw or a pesticide. It’s a patch.

Kairos Futura and the Aspen Center for Environmental Studies (ACES) are partnering to treat 5,000 trees this Saturday, May 30. The goal is simple in theory, complex in execution: stop the beetles from overwhelming the forest. Volunteers will spread out across the mountain’s backside starting at 11 a.m., placing pheromone patches on the trees. These patches send a chemical signal telling the beetles, "We’re already here," effectively tricking them into thinking the tree is occupied.

The question is whether this temporary fix can hold against a climate-driven invasion.

“As a consequence of human actions, their activity has gotten out of scale from what we’ve seen historically,” said Adam McCurdy, Forest and Climate Director for ACES. “With that, we are looking at areas where we can try and help bring things back within the range of historic alignment … The hope is that people are able to walk away from this with a better sense of what the impacts are on our local landscape and how climate is impacting us and feel they have some agency and some ability to influence this.”

The science is straightforward. Bark beetles use aggregation pheromones to call their kin. Once a few get into a tree, they release a signal that attracts hundreds more to swarm and overwhelm the tree’s defenses. The upcoming event places anti-aggregation pheromones in a grid pattern. It’s a chemical fog of war designed to confuse the swarm.

“The goal is not a forever project,” McCurdy said. “The goal is to help get the trees past the outbreak stage.”

It’s a pragmatic approach. We aren’t trying to save every tree forever. We’re trying to keep the forest alive long enough for it to recover. The event itself is designed to make the work feel less like manual labor and more like a mission. Participants will be hunting for "Forest Relics" — art pieces hidden by Kairos Futura artists — while they patch sectors of the forest. It’s a scavenger hunt with ecological stakes.

“The beetles kill silently,” the event’s press release notes. “They bore into bark, sever a tree’s water supply, and leave it standing, still green, but dead.”

For the locals, this is personal. Ajax is the mountain behind our town. It’s the view from the gondola, the backdrop to our ski season, the ecosystem that keeps our water and our air in balance. When the Douglas-firs go, the landscape changes. The soil dries. The snowpack shifts. This isn’t just about trees; it’s about the integrity of the valley we live in.

The event kicks off at 11 a.m. with the work, followed by a party from 4:30 to 6:30 p.m. with food, drinks, and prizes. It’s Aspen at its best: turning a crisis into a community event, blending science with socializing. Volunteers will be initiated into the "First Forest Division," receiving a badge hat and a sense of accomplishment.

But the real test isn’t the party. It’s whether 5,000 trees treated with pheromone patches can withstand the next wave of beetles. Climate change has created conditions for outbreaks on a scale we haven’t seen before. This is a stopgap, a bandage on a wound that’s bleeding from the inside.

McCurdy believes the community’s involvement is the key to long-term resilience. By getting people out there, patching trees, and finding hidden art, they’re building a connection to the land. They’re learning how the forest works, one patch at a time.

“We are looking at areas where we can try and help bring things back within the range of historic alignment,” McCurdy said. “The hope is that people are able to walk away from this with a better sense of what the impacts are on our local landscape and how climate is impacting us and feel they have some agency and some ability to influence this.”

The outcome hangs in the balance. But for now, the community is ready to fight.