The Mount Wilson Observatory and communications equipment at the summit of Mount Wilson were protected both by actions taken by firefighters during the Eaton Fire and treatments applied months before the fire. (USDA Forest Service video by Andrew Avitt)

At just under 6,000 feet, the Mount Wilson Observatory and communication site sit within the San Gabriel Mountains of the Angeles National Forest in Southern California.  Mount Wilson is known in Pasadena for its stellar views of the night sky and scenic backcountry trails. Drivers can actually see the trails and extensive network of critical communications from Interstate 210 nearby.

Fortunately, all of this infrastructure and access would come in handy when the Eaton Fire approached the southwest perimeter of Mount Wilson on Thursday, Jan. 9.

Unexpected but not unprepared

Forecasts hadn’t anticipated how quickly the Eaton Fire would reach Mount Wilson that morning. But by 9 a.m. on Jan. 7, it became clear firefighters would only have a few hours to prepare — rather than a day or two as previously forecast.

Unusually strong Santa Ana winds brought prevailing 80-100 mph downslope winds that devastated Altadena and other nearby urban areas. But just two days later, most of the fire’s spread was occurring in the canyon southwest of Mount Wilson, rather than in the urban areas below.

Two federal firefighting teams— Kings River Hotshots and Angeles National Forest Engine 310 — as well as an array of state and county resources worked quickly to strengthen the fire’s perimeter. To withstand the approaching fire front, everyone prepared for a strategic firing operation to create a buffer along Mount Wilson’s southern edge.

Preparing for a strategic firing operation entails creating fuel breaks near structures, roads or other infrastructure, making them easier to defend when fire reaches them. First, excess fuel is cut away with chainsaws. Then, to add an extra layer of protection, crews use drip torches to burn the remaining vegetation. This creates a buffer or a void of burnable vegetation before the main fire arrives.

“We did a little bit of defensive firing, but it was a very light amount,” said Brad Rafeedy, a fire management officer from the Klamath National Forest and a branch trainee on the Mount Wilson portion of the fire. “We're talking about three folks here, so just three drip torches. We wanted to use very little fire when fuels are in the critically dry condition that they're in right now. It doesn't take a lot of fire, especially when you have the winds that we had.”

Crews had already been cutting as much brush as they could from below the parking lot and towers as the fire burned in the drainage below Mount Wilson. As the fire pushed up quicker than anticipated, fire leadership brought in Kings River Hotshots from the Sierra National Forest to perform a small strategic firing operation below the communication infrastructure.

Quick thinking and the right resources

The operation ended up being a profound success — the fire impacted none of the infrastructure at Mount Wilson. Firefighters also picked up the few small spot fires that had the potential to ignite the other side of the ridge.

Rafeedy was quick to point out just how technical this operation was—it required quick thinking and the right assortment of resources, with a high-level understanding of fire behavior and how to use strategic firing operations to protect structures effectively.

“The crews performed this operation with a lot of expertise and good timing and even maturity is what I would call it,” Rafeedy said. “They had the experience to do it well…and we were able to immediately start mopping up and catching slop overs.”

While federal crews performed the operation, state and county crews assisted with holding the fire below the ridge. They picked up hot spots and made sure the fire stayed exactly where they wanted it.

“We had a plan in place and implemented it when it was time, not too soon and not too late,” Rafeedy added. “These crews did what they’re trained to do while working well with other resources. It couldn’t have gone better.”

The actions taken to protect Mount Wilson represent the most fundamental tool that firefighters have when fighting fire — modifying the vegetation so it can better withstand fire. In these circumstances, it helps to do this type of work before a fire impacts an area.

Using fire to prepare for fire

The USDA Forest Service is leading the nation to make prescribed fires safer and more effective. We know that to protect communities and natural resources, we need to restore healthy, resilient, fire-adapted forests by using mechanical thinning and returning beneficial fires to these landscapes. Our work has taught us that we must work in the right places in the right ways to achieve the greatest good for both people and the environment.

These lessons certainly bore fruit on Mount Wilson, where the Forest Service had completed a number of fuels projects prior to the Eaton Fire, reducing fire intensity by limiting the amount of fuel present to burn.

These treatments have been taking place for decades, according to Angeles National Forest Fire Chief Robert Garcia.

“Being identified as a high-risk landscape gave us the opportunity during the last two years to really ramp up our efforts — increasing the pace and scale of how much work we're doing and where we're doing that work,” Garcia said.

“The investments we made for years, even decades, in a combination of treatments at Mount Wilson really paid off, especially since Mount Wilson has been threatened by several large fires just in the last couple of years with the Bobcat, the Bridge and now the Eaton Fire,” he continued.

With this history of wildfire in the Angeles National Forest, Garcia recognizes that more work is needed to prepare for the next one, whenever it may come.

“I think this is an example of the need for an all-hands, all-levels-of-government approach,” Garcia said. “Because there is no silver bullet, there is no simple treatment. But all these different pieces are part of the solution — the fuels and vegetation management, the home hardening, ordinances around construction and how we respond together in a unified way.”