When wildfire meets thinned forests

Wildfire. It’s not if, but when.
That’s the paradigm for most Western states affected by wildfire each year. California routinely tops the annual list for most acres burned and largest fires. It also has the most homes and private property at risk.
It’s no surprise that the state boasts one of the largest wildland firefighting workforces. Some 27,000 federal, state and local firefighters are involved in putting out these fires each year. And when they’re not fighting fire, often those very same firefighters maintain fuelbreaks and treat forests in preparation for future threats as part of the Forest Service’s Wildfire Crisis Strategy.

Sometimes, it’s that prior groundwork that makes all the difference.
Two of this year’s larger fires in Southern California — the Line Fire and the Bridge Fire — provide examples of just how wildfires interact with these areas, and how treatments can be used as opportunities to defend homes and communities.

Angelus Oaks and the Line Fire
Jamahl Butler, deputy forest supervisor on the San Bernardino National Forest, manages 850,000 acres of wildland hills and mountains, surrounding the inland empire east of Los Angeles.
“Historically, we’ve been fighting fire in these mountains in Southern California for decades,” said Butler. But the nature of that fight has changed since the beginning of his career.“In 2001, a 20,000-acre fire, felt huge. Since then, they’ve gradually gotten bigger and more complex. Now we have million and million-and-a-half-acre fires.”
So, when five wildfires started in Highland, California, near the San Bernardino National Forest on Sept. 5, the Forest Service and local fire departments wasted no time responding to and extinguishing four of the five. The fifth one wouldn’t be so easy.
Wildland firefighters are experts at locating and suppressing wildfires. The Forest Service estimates that 98% of wildfires that start on national forests are kept small and successfully suppressed within 48 hours.
Unfortunately, it only takes one fire burning in the right conditions to pose a serious threat.
On a hot, dry day during an uncharacteristically hot, dry season; high winds in steep terrain whipped up the fifth fire—the Line Fire.
Those conditions were all the Line Fire needed as it spread quickly toward the 500-resident community of Angelus Oaks.

“Firefighters defending communities, like Angelus Oaks, will tell you there’s a lot that goes into stopping an oncoming fire,” said Butler. “What many people don’t often realize is a lot of the work has been done months or even years in advance.”
In the case of defending Angelus Oaks, fuels treatments were essential.
“We had implemented some prescribed burning and forest thinning on the west side of the Angelus Oaks community, which served as a fuelbreak. And it was there the fire slowed down,” Butler explained. “We were able to make a real stand near that community.”
Wildfire mitigation work – including prescribed fire and mechanical thinning — all make a difference. The San Bernardino National Forest treated nearly 6,000 acres in 2024 with this defensible use in mind.
Mitigating wildfire risk to small towns like Angelus Oaks is a priority. That focus also includes larger mountaintop communities like Big Bear, Lake Arrowhead, Running Springs, and Crestline, which benefited from past fuels work during the Line Fire.

Wrightwood and the Bridge Fire
A few days later and about 40 miles away, a similar scenario was playing out near the small community of Wrightwood, population 5,000. The Bridge Fire, also driven by extreme weather and landscape conditions, grew nearly 10 times its size in one day.
At 5:15 a.m. on Sept. 10, the Bridge Fire was reported at 2,995 acres. By 6 p.m., the fire had grown to 34,240 acres.

Eventually, the Bridge Fire would meet more Forest Service fuelbreaks — along the Big Pines Highway and the Blue Ridge, where trees had been thinned out five years prior.
“With these treatments, we saw the highest level of success,” said Ron White, who leads the Fire Prevention and Fuels Program on the North San Gabriel National Monument.
Anytime the fire interacted with these preventive projects, there were positive outcomes.
When the fire reached project areas — where brush was cleared, chipped, and scattered back on the landscape — fast-moving wildfire spreading through the tops of the trees dropped to the ground, slowing spread and allowing firefighters to work.
“The projects did exactly what they were supposed to do.” said White. “Then, in other areas, where we had recently used prescribed fire, the Bridge Fire essentially was dead in its track and did not pass through those areas. There, you can notice a sharp difference between where our projects start and stopped. And there is a wild difference in tree mortality.
White credits these treatments as a major reason why firefighters could defend the Wrightwood area.
Other treatments were spread out across a wide area that included Camp Comiches, Verdugo Pines Camp, Lions Camp at Teresita Pines, Mountain High resort, and Table Mountain up through NASA’s Jet Propulsion Lab.
Since White first started with the Forest Service as a wildland firefighter on a hand crew 23 years ago, he said he’s seen a real shift in how the agency plans to reduce wildfire risk in the last few years.
“Suppressing fire will always be a focus. But now the risk mitigation and fuels treatments are becoming a bigger and bigger part of the strategy,” said White.
But with that increased emphasis comes additional challenges.
“The years are becoming busier for firefighters on the Angeles National Forest, and it’s those same employees who often implement fuel treatment work, too,” said White.
“The agency’s Wildfire Crisis Strategy has brought a lot of additional funding, which has enabled us to plan on a large scale and to work with partners — like the Rivers and Mountains Conservancy and the National Forest Foundation — to get the work done.”
The Big Pines area, which helped firefighters defend Wrightwood and other treated areas around the Bridge Fire, had been planned for years. For the Forest Service, the additional $1 million from the Inflation Reduction Act and the $1.9 million in state and private funding through the National Forest Foundation were essential to implementing the Big Pines treatments.

Expanding the work to meet the risk
The Forest Service and its partners have long understood that projects like the ones near Angelus Oaks and Wrightwood are one of the best ways to help lower wildfire risk to communities.
As a part of that strategy, the Forest Service and its partners have identified four million acres in Southern California to reduce risks by using prescribed fire and mechanical thinning.
It’s estimated that in Southern California, 10% of the country’s population (25 million people) is just a short drive from a nearby national forest, making these treatments an even better investment.
Fuel treatments can lower risk to people, and also cell towers and communications sites, recreation areas, archaeological sites, infrastructure and ecosystems.
Early results of this strategy show a notable uptick in this work with the Forest Service breaking its record of most prescribed fire treated acres this year.
These recent success stories near Angelus Oaks and Wrightwood are critical to reaffirm land managers’ understanding of how to effectively reduce communities’ wildfire risk. They also serve as an important illustration to residents, especially those that may be a little apprehensive about prescribed fire and tree cutting.
“In some of these treatment locations, there were people who had reservations. Mostly for aesthetic reasons. They were concerned about how much fuel we were removing,” said White. “But then, after this fire went through, they were relieved and maybe understand better… now that they finally got to actually witness our goals in reality.”