Grass growing out of the ashes in the burn scar left by the NCAR Fire. April 9, 2022. Credit: Harry Fuller

Dan Burke, director of Boulder Open Space and Mountain Parks (OSMP), didn’t expect he’d be presenting to the Board of Trustees about another wildfire just three months after the Marshall Fire destroyed more than 1,000 homes in southern Boulder County late last year.

But as Burke said during Wednesday’s board meeting to discuss mitigation efforts surrounding last month’s NCAR Fire: “Emergencies and disasters tend to not adhere to our human constructs of schedules and timelines.”

However, according to OSMP staff who discussed the response to the March 26, 2022 wildfire that burned nearly 200 acres of city open space near Boulder’s NCAR Mesa Laboratory, it was the human effort behind the department’s fire mitigation program that proved essential in keeping the fire from becoming a tragedy like the Dec. 30 disaster.

Luckily, wind speeds during the NCAR Fire weren’t as strong as they had been during the Marshall Fire, when gusts topped 100 miles per hour. The lower northerly winds allowed firefighting aircraft to respond by dropping retardant to keep the fire boxed in.

As climate change extends Boulder’s wildfire season, lessons learned from close calls like the NCAR Fire will be essential in preparing for the next disaster. And the insight shared during this week’s board meeting demonstrated the importance of fire mitigation. Thanks to previous OSMP efforts to reduce flammable vegetation and undergrowth, the NCAR Fire was slower and less intense than it otherwise would have been.

Ranger Senior Manager Burton Stoner recounted the early moments of OSMP’s response to the blaze that began around 2 p.m. in Bear Canyon. He said staff worked quickly to evacuate everyone off nearby trails, ferrying people to safety in the back of pickup trucks and trekking up Bear Peak to assist a group of hikers.

Their next priorities were alerting residents in houses closest to the fire and closing trails that could be in its path. Stoner said communicating to the public, including keeping an up-to-date evacuation map, was also a top priority. He praised the first responders to the scene of the NCAR Fire, including OSMP staff, for their quick response.

A slide from a presentation during the OSMP Board of Trustees meeting on April 13, 2022, shows mitigation boundaries within the burn area of the NCAR Fire that burned through nearly 200 acres of city open space last month. Courtesy of City of Boulder

Mitigation matters

But while the immediate response to the blaze was crucial in its containment, OSMP Senior Manager of Vegetation Stewardship Chris Wanner emphasized the importance of past fire mitigation efforts in limiting the spread of the NCAR Fire. OSMP employs two fire mitigation tactics, which Wanner said helped create better firefighting conditions: thinning forested areas and allowing livestock such as cattle to graze grassy areas.

These actions reduce the amount of fuel a potential wildfire can burn, according to Wanner. A thinned forest offers easier access for firefighting crews and slows a fire’s movement. Grazed grassland is shorter, which means shorter flames. Wanner said flames typically reach four times the height of their fuel source.

Wanner also emphasized that wildfires have long occurred naturally in the Boulder area and can produce many ecological benefits if controlled properly.

“These are fire-adapted ecosystems. They’re made to burn, and they will burn,” he said. 

Without controlled burns, the ecosystems will burn uncontrollably and unexpectedly. Regularly scheduled burning reduces the risk of runaway fires and facilitates plant growth.

OSMP has done fire mitigation on more than 600 acres of city open space over the past decade. Much of the NCAR burn area had undergone fire mitigation, according to a map that Wanner shared during the meeting. He also shared pictures contrasting a mitigated part of the burn area to an unmitigated part. The mitigated section appeared significantly less impacted than the unmitigated section, which had more scorched ground and understory damage.

Jeff Haley, director of trails and facilities, said OSMP will continue its fire mitigation program and review its wildfire response playbook following the NCAR Fire. He also said trails will have more staff present to ensure visitors’ safety. OSMP will share more of its NCAR Fire reflections at the April 26 Boulder City Council study session.

Open Space Trustee David Kuntz asked whether staff have considered more prescribed burning as a mitigation technique. Wanner said they are trying to do more prescribed burns, including the area by the NCAR water tank. He also mentioned Boulder had recently received designation as a “significant user” by the state, which should speed up authorization for prescribed burning. A significant user of prescribed burns, as defined by Colorado regulations, is a government agency that manages at least 10,000 acres of land and plans prescribed burns that would generate more than ten tons of inhalable particulate matter (PM 10) in a year.

Wanner said the NCAR Fire wasn’t too different from a prescribed burn, as the fire was patchy and burned mostly undergrowth due to earlier mitigation. He doesn’t think OSMP will have to do much restoration. In fact, burning undergrowth is good for plant growth. He shared a photo showing part of the burn area with native plants sprouting up just a week after the fire.

“It’s even greener and lusher now,” he said.