CORDILLERA — The rugged, pine-and-sage covered mountains framing $5 million homes in this wealthy community have already lost their snow, and the thick underbrush crackles underfoot. Trevor Broersma and Jim Rabun know these 7,500 vulnerable acres will need every tool they can assemble to fend off calamitous wildfires in the driest Colorado spring on record.
So this sunny morning above the community horse stables, Rabun jockeys a remote control box hung from his neck to guide Cordillera’s new $70,000 robot mower as it churns up a 25-degree slope and shreds native grasses and 1-inch scrub oak trunks. Within a week, Broersma and the Cordillera Metro District staff will start drilling holes in about 1,000 aspen and Douglas fir to hang stopwatch-size smoke and particle sensors for an early warning system.
Over lunch back at the office, Broersma is researching drones that can carry 30 gallons of fire retardant and help slow a budding fire detected in rugged terrain until human firefighters can hit it. Can snowmaking guns at nearby ski areas be employed as fire suppression? He watches computer simulations of where weather and soil conditions will push any Eagle County wildfire spark. Staff coordinate with Eagle Valley Wildland outreach to prod reluctant homeowners to cut trees and remove wood mulch from flower beds.
Anything and everything to prepare, especially this year, in a community with only one paved access road to deliver firefighters and evacuate residents.
“We’re buying 45 minutes of time,” Broersma said.
Everyone wants to operate the slope-chewing robo-mower. But what Broersma and county officials are most enthusiastic about this month is the arrival of the thousand smoke and particle detectors from Dryad Networks, a German company. Cordillera, with about 700 residents, will be the second community in the nation to install them as general fire detection, after a vulnerable Florida neighborhood.
Staff will spend the next weeks hanging the sensors deep in the woods or at meadow’s edge up and down Cordillera’s 2,000 feet of elevation gain. When the device senses a sudden change nearby in air quality or particulate density, it sends the exact GPS coordinates to a command center at the metro district offices and to the phone screens of everyone on staff. If wildfire smoke from California or Canada has already permeated Eagle River Valley, the sensors can start each day with a new baseline level to avoid false positives.
“I have full confidence it will prove out, and then hopefully we can work together to figure out how to get them all around the county,” said Broersma, who lives across the highway from Cordillera in a different metro district.
For Cordillera leaders know full well they come to the looming firefights with more resources than many Colorado communities. The $300,000 to $400,000 sensor system was affordable with a 2025 budget surplus.
“How is it scalable to communities? I think that is a great question,” Broersma said. “Yes, we are well funded. But this system can be scaled to any community’s funding model.”
Cordillera is working closely with Eagle Valley Wildland to demonstrate the technology and then test where else it could be effectively employed with county funds. The fire protection district tries to democratize wildfire mitigation with offers like a free home defense assessment to anyone in the county.
Cordillera notes that wildfires won’t just come into their community. They will also roar out of their small community and on toward mixed neighborhoods of mobile homes, townhomes and residences on the way to Edwards 5 miles east. About 7% of the local workforce lives in Eagle River Village mobile home park down U.S. 6.
“We had a county stakeholder meeting, and somebody asked us, should we be thanking Cordillera? And really, in a way, fires are going to go west to east,” Broersma said. “So yes, Arrowhead would thank us, and we would thank Diamond Star and Frost Creek to the west in Eagle County if they were also going to put in this system.”
Jeff Rasmussen, a Colorado state fire protection chief, said that while some counties’ pursuit of firefighting drones may be premature, and run into practical blockades from the Federal Aviation Administration over firefighter safety, state officials are happy to see communities trying sensor technologies other counties can use.
The state’s use of drones so far is limited to wildfire detecting, and may soon be expanded to helping map fire spread and behavior in real time, Rasmussen said. Using swarms of tank-carrying drones could help slow down a budding fire, he said, but also poses new dangers.
A 30-gallon tank brings a drone up to hundreds of pounds in weight, flying in fire-exaggerated weather over the heads of response teams and equipment. Flight paths must be coordinated with the FAA, and national parks and forest officials have varying rules about flyovers of remote lands. Nor does anyone want heavy drones running into bucket-dragging helicopters.
The large-scale sensor experiment, though, is valuable, Rasmussen said, and Cordillera and Eagle fire officials are doing well to demonstrate new approaches.
“If this is something that works, and those guys are able to provide proof of concept and really get an early detection on fires, then certainly the state would want to look at implementing that on a bigger scale,” he said. Analysts will want to see how close together the sensors must be placed, how accurate they are in locating smoke sources in high winds, what the cost turns out to be per acre of coverage.
“So I have a lot of questions about it, but that is something I think is super interesting,” Rasmussen said.
Designing for disaster
High technology cannot completely supplant boots on the ground. That’s why Rabun is spending many of his spring days walking 10 yards behind the tireless, tank-tracked robo-mower. He could sit up to 1,000 feet away with the controller in a climate-controlled pickup cab, but he wants to guide the mower around boulders and deep crevices.
Cordillera’s goal is to mow 25 miles of fire breaks that can slow flames and maintain the community’s defensible space. Mowing the breaks not only deprives wildfires of fuel, it also opens up terrain for drones or helicopters to drop retardant to further fortify the defense. Dropping retardant on fully grown brush provides only about 30% resistance, Broersma said, while dropping it on more receptive mowed terrain boosts the protection to about 80%.
The golf-course community has multiple hidden designs that support fire suppression. Dozens of elk take April sun siestas around homes and ponds, and the golf course water features are carefully planned. The middle depth at up to 18 feet is enough to accommodate a helicopter-towed water bucket in fire season. Yet they have a shallow shelf around the edges allowing the elk to wade and drink easily.
The mowed fire breaks also support the elk, with the blessing of Colorado Parks and Wildlife. Elk and deer flock to the rolling strips for tender grasses.
Rabun, Cordillera’s community operations supervisor, can mow acres in a day. Hiring the job out to another company would cost up to $5,000 a day, Broersma said, so the community board felt the robo-mower would pay for itself quickly. It’s cheaper than even one worker’s compensation claim for an employee injured swinging a chainsaw on a 40-degree pitch.
Installing about 1,000 solar-powered smoke sensors will be a team effort beginning in April and running through summer. It’s also a rolling experiment, as the staff works with Eagle Valley Wildland to adjust the optimum placement: Should sensors be dispersed widely in deep forest, or grouped more tightly along meadow borders closer to vulnerable homes?
Current weather and snowpack conditions are top of mind at Cordillera, but nightmares of recent nearby fires are never far from the surface. The Sylvan fire near the local state park in 2021 was terrifying for the surrounding communities. Southern California’s devastating Palisade fire also sent shock waves, as communities saw how quickly fire suppression breaks down when water lines melt and high winds overwhelm planning.
The Sylvan fire was smoldering in remote country for four to six days before locals noticed it and responded.
“That’s where the sensors come in,” Broersma said. “It’s the nose of the forest.”