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Study: More homes are burning in fire-prone areas of Montana

Bridger Foothills Fire
Posted at 3:36 PM, Dec 18, 2020
and last updated 2020-12-19 10:53:49-05

MISSOULA — As people build more houses in Montana’s wildland-urban interface, more homes have burned and will burn in wildfires unless homeowners take precautions.

In November, Bozeman-based Headwaters Economics published a study showing the number of homes destroyed in wildfires is increasing. Kimiko Barrett, Headwaters Economics program coordinator, said that information should be publicized more because it reflects the social and economic toll of wildfires better than the number of acres burned.

“To date, there is no source that we are familiar with that publically releases information on structures lost. It’s really hard to find, which is a shame because it’s so important,” Barrett said. “It’s publically available, but to dig through that kind of information, we had to use a whole tech team.”

By pulling numbers buried in annual wildfire incident reports, researchers found wildfires burned more than 89,000 structures nationwide between 2005 and 2020.

What’s striking is three-quarters of those structures burned in just the past five years. The largest number of structures, almost 25,000, burned in 2018. That was when electrical transmission lines started the Camp Fire that swept through Paradise, Calif., its 19,000 buildings accounting for most of the national total.

The five-year trend for Montana is less obvious. However, excluding 2012, this year, and 2017, the year of the Lolo and Rice Ridge fires, saw the largest number of buildings destroyed with 169 and 142, respectively.

This year’s numbers include 68 buildings burned in the Bridger Foothills Fire just outside Bozeman and 48 burned in the Bobcat Fire near Roundup. The losses placed both fires among the top five of Montana’s most destructive fires since 2005.

Barrett cautioned that numbers from 2020 aren’t exact because the year isn’t over so researchers had to use the National Interagency Fire Center Year-to-Date report, which provides only raw data. But they provide a conservative count, Barrett said.

The Montana wildfire that destroyed the most buildings was the 2012 Dahl Fire in the Bull Mountains south of Roundup, which burned 223 structures. But, of those, only 73 were homes. That’s another problem with the incident report summaries -- they don’t provide a precise picture of true loss.

“They don’t differentiate which buildings are homes. It’s a huge difference if it’s a garage that burns down as opposed to a house for a family of four,” Barrett said.

Government agencies, research institutions, universities, and other groups have seen the trend of building loss and are working on improving the methodical tracking and reporting of such information. But fire policy and procedure can be slow to change, especially when so many agencies and districts are involved.

But as the years have passed, homes accounted for more of the buildings burned, and that’s going to increase in the future as more people move in and fires worsen.

One reason is climate change is increasing the risk of catastrophic fires by causing long-term drought, parching forests or grasslands. Then, all it takes is for a spark to occur during an extended period of summer heat and high winds and you have a recipe for a wildfire that can burn a vast area that can include communities, aided by wind-borne burning embers that can land a mile away.

But a bigger reason is housing development is increasing in wildfire-prone lands. Another recent Headwaters Economics study found that a third of all Montana homes are already in areas with moderate to high wildfire risk, and more are on the way.

For example, so many structures were lost in the Bridger Foothills Fire because more than 80% of area burned was private land. The fire had more to do with the condition of private property than that of the adjacent national forest.

Using Montana Department of Revenue data from 1990 and 2018, Headwaters Economics found the number of homes built in moderate to high wildfire hazard areas has nearly doubled. With community planning nonexistent, the rate of housing growth in moderate and high hazard areas is far outpacing the rate in less risky areas.

Flathead County is in the worst shape with almost 8,900 homes built since 1990 in both moderate- and high-risk areas, although Missoula and Ravalli counties aren’t far behind, adding about 8,000 each.

But while less than 20% of the new homes in Flathead and Missoula counties were built in high-risk areas, 60% of the new homes in Ravalli County are in high-risk areas positioned to burn in the next Lolo Peak or Roaring Lion Fire.

“It’s not just climate-change-driven,” Barrett said. “It’s also people building and pushing their way into harm’s way where wildfire occurs. It’s the fastest-growing land-use type in the country. And in 2020, there’s been a lot of COVID-caused urban exodus pushing more toward those lands. If you’re going to build your house in a place that’s going to burn, it’s not a matter of if – it’s a matter of when.”

Barrett pointed out one other complicating factor. As more people move into wildfire-prone areas, the greater the chances are of a fire starting. According to a recent study, humans caused 97% of all wildfires in the WUI and more than doubled the length of the fire season.

For the safety of residents and firefighters, fewer homes should be built in fire-prone areas. But even in risky areas, homes don’t have to burn. Homes built with fire-resistant siding and roofing stand a better chance of surviving and don’t cost much more to build. In addition, clearing trees, shrubs, and debris within 100 feet of a house – the home ignition zone – can reduce the chances of a wildfire reaching a house.

Contact reporter Laura Lundquist at