Boulder, Colorado wakes up to the threat of worsening wildfires

The famously well-planned and livable city escaped last week. But it's especially vulnerable to fires from nearby forests, experts say.

Photograph by Amanda Windischmann
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Pyrocumulus clouds from the East Troublesome Fire rise above Coal Creek Canyon in Colorado on October 21—just before the fire crossed the Continental Divide and roared into Rocky Mountain National Park.

Photograph by Amanda Windischmann

It’s been a sad, smoky few months in Colorado. Although the blazes in California and Oregon received more national attention over the summer, Colorado has been burning since July.

Three of the largest fires in state history have burned this year. The Cameron Peak fire, now the largest in state history, has burned more than 207,000 acres since mid-August. The second-largest blaze in state history, the East Troublesome Fire, started on October 13—and a few days later grew by 140,000 acres in a single night. That fire, spurred by intense winds, jumped the Continental Divide, traveling across more than a mile of rocks and tundra shrubland and into Rocky Mountain National Park. It had burned more than 190,000 acres—and an estimated 300 to 400 houses—before a snowstorm provided some relief on October 25.

Nearly 700,000 acres—almost 1,100 square miles—have burned in Colorado this year. Almost a third of that happened in October, well outside what’s long been considered the normal fire season.

Active fires since October 19, 2020


The same factors that led to disaster in California—climate change and a legacy of misguided forest management—are at play here too. Almost all of Colorado is now experiencing severe, extreme, or exceptional drought. And according to the Denver Post, crews have not yet begun $4.2 billion worth of forest thinning and other projects the state has deemed “critical to protect people and property from fires.”

Where I live, in Boulder, mid-October temperatures were still in the 80s. Ash had been falling for months and firefighting jets flew overhead most days—but until recently the fires themselves felt like something that happened elsewhere. Boulder was in the national news for another reason: On October 13, U.S. News and World Report named it the best place to live in the entire country.

Since I moved here, in 2002, the population has increased by about 13 percent, to 106,000, and home prices have skyrocketed. Much of that growth is people who, like me, moved from larger metro areas—New York, Los Angeles, the Bay Area—for Boulder’s quality of life. The median price of a home here is now about $1.125 million, and houses frequently receive multiple offers within hours of listing.

Meanwhile, in the hills west of Boulder, the ponderosa pine forests are overcrowded and unhealthy, and they haven’t been allowed to burn in their natural fire cycles for more than a hundred years. When they do finally burn, climate change will increase the odds of those fires getting big fast, like the ones this year. The city and county have been working to thin some of these areas, with selective logging and prescribed burns. But it takes time, money, and coordination between a host of different stakeholders.

It’s a question of when, not whether, a fire will come roaring into Boulder itself. Yet few people here think about their risk. I didn’t used to myself, until lately.

Four days after the “best place to live” award, under high winds and a red flag warning, a new fire began, and a cloud of smoke mushroomed from a mountainside northwest of town. Christened the CalWood Fire for the beloved outdoor education center where it ignited—cause unknown but undoubtedly human—the blaze quickly grew. Small communities in the foothills evacuated.

Then the CalWood fire raced downhill from the mountains to the plains. It became the biggest fire in Boulder County history, at more than 10,000 acres. The flames briefly crossed US 36, a main thoroughfare that heads north out of Boulder.

People fled as quickly as they could, loading horses into trailers, packing dogs and cats and valuables into cars. It seemed as though the fire might continue to spread east and south, into Boulder. City residents who rarely worry about wildfire became uneasy.

For only the second time in the 18 years I’ve lived here, on the southwestern side of town, my family packed go bags. So did many people I know.

On the edge

Boulder sits where the plains meet the mountains at a sharp angle, and it’s surrounded by a greenbelt—preserved in the 1960s by prescient city planners—that’s key to its allure. But all that lovely open space also poses a risk, even if we tend to underestimate it. People who work on wildfires talk about the wildland-urban interface, or the WUI (pronounced woo-eee). It’s where neighborhoods meet natural areas. It’s where people have increasingly chosen to live, and where wildfire risk is highest.

In Boulder, residents of the flatter, more paved neighborhoods—the city proper—tend to think of the WUI as being up in what city planners call “the mountain backdrop.” That’s a fallacy.

“The city of Boulder is the definition of the WUI,” says Chris Wanner, forest ecologist for Boulder’s Open Space and Mountain Parks department. “We are right here. But I think it’s somewhat easy to get complacent when you feel like, ‘I live in the city, it’s not going to impact me.’”

This sentiment was common in an unscientific poll I took, questioning a couple dozen friends who live on the west side of town. “Do you feel like you are at risk from wildfire?” I asked, the Friday after the CalWood fire began. (That blaze was followed the next day by another local fire, and more mountain evacuations.)

“I've lived in Boulder on and off for 25 years and this is the first year I've worried about wildfire in Boulder,” one friend said. “I generally feel this is a mountain community issue, but the jump of CalWood across 36 was a bit of a reality check,” said another.

Jennifer Balch, a fire scientist and director of the Earth Lab at the University of Colorado Boulder, points out that while flood plain maps are commonplace, “we don’t have fire maps that direct development and insurance in the same way, so you don’t think about it when you buy your house.” Balch is also my neighbor; we both live near a trailhead where a five-minute walk up a grassy hill takes you into ponderosa pine forest. It’s one of my favorite places in the world, and it’s primed to go up in flames. I was curious how Balch thought about the risk.

“At some point, the conditions are going to be in the right place,” she said of our neighborhood and its chances of burning. She pointed out the line of junipers that create a privacy barrier between the trailhead and a couple of homes that back to it. Junipers can burn fast and hot, shooting off embers. Yet they’re common in neighborhoods throughout Boulder that were built in the ‘50s and ‘60s, when the fast-growing trees were popular.

Balch showed me a new app called Defensible that maps fire risk on a color scale, building by building, across all 11 Western states. Red is the highest risk, blue is the lowest. Both our homes were orange.

“Everybody has their own risk tolerance,” Balch said, “and on some level some of that doesn’t make any sense.”

The time to prepare

Over the past 15 years, the city of Boulder has thinned forests and conducted prescribed burns on 2,000 acres. That kind of work can cost millions of dollars. But it’s certainly a lot less costly than putting out a fire that’s racing into town, let alone the potential damages if the fire can’t be put out in time. As I watched the progress of the CalWood fire last week, I was reminded of the Waldo Canyon fire in the summer of 2012. It began in the hills outside Colorado Springs, but then it swept into the city, burning nearly 350 homes in suburban subdivisions.

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Over the weekend, snow put a damper on some of the Colorado fires. This photo shows an area that had been in the path of the Cameron Fire, which also affected Rocky Mountain National Park.

People do incredibly stupid things, and they are not going to stop as the weather gets hotter and drier. Balch recalled watching with horror, not long ago, as a man put out a cigarette 20 feet along a trail near our houses. “I was like, ‘You made sure that’s out, right?’” she said. All summer, my own sleep had been interrupted by fireworks—a favorite pastime in a nearby student neighborhood. Even as the CalWood fire burned, I woke to the sound of fireworks exploding, feeling overwhelmed by a mixture of rage and dread. It does not take much to set bone-dry vegetation ablaze. And bone-dry vegetation is increasingly likely in the age of climate change.

As the CalWood Fire crept toward Boulder, Lori Peek found herself in the evacuation zone; she fled with her husband and dog “as spot fires ignited the parched land” on the mountainside behind her house. Peek happens to know a lot about risk, as a sociologist who studies disaster and directs the Natural Hazards Center at the University of Colorado. In a blog post she wrote that while waiting to learn if her house was still standing, she urged people to recognize the risks they faced and “make provisions.”

“Please don’t wait,” Peek wrote. “The time to prepare has always been now.”

My family and I were lucky last week; the fire never reached our neighborhood. Peek was lucky too; her house survived. But some two dozen other dwellings burned in that fire, along with hundreds more in the other blazes.

The fires near Boulder, at least, are now under control, and the region is blanketed in snow. But the risk remains. “Every time one of these fires happens,” says Wanner, “it’s like, it could’ve been a little bit closer to town. For sure.”