Despite a wave of lightning strikes that have passed through on a warm August evening, the patrol flight over the wilderness reveals no signs of smoke.

Only wisps of mist known as water dogs float above the forest canopy, evidence of recent fleeting rains.

It is an odd year. The forest is as green as Ireland at a time when it is usually cured and primed for fire.

But from 8,000 feet, the footprint of fire is everywhere in Montana’s Bob Marshall Wilderness. It is a mosaic of contrasting shades of green, reflecting different ages and species of trees on a single mountainside. A sea of lodgepole pine has emerged from huge fires that burned across Morrison and Lodgepole creeks more than seventy years ago. But nearby there are patchworks of burned snags poking from the green of a young forest floor.

These areas are products of a twenty-year-old wildfire-management program in the 2-million-acre Bob Marshall, Great Bear and Scapegoat wilderness areas.

“Most people don’t realize that over the last five years even, we’ve burned over 40,000 acres in here,” said Steve Wirt, a veteran wilderness fire manager on the Flathead National Forest.

Since the program was established in 1981, about 257,000 acres have burned in the wilderness. It’s a striking number when compared with just 5,000 acres that burned between 1930 and 1984.

It’s a testament to the effectiveness of the firefighting machine that developed after wildfires consumed more than 3 million acres in Idaho and Montana in August 1910.

That infamous year triggered the creation of fireguard stations, trail systems, lookout towers and telephone lines in the wilderness. Small armies of firefighters lived in the wilderness in the summer, and by the 1940s smokejumpers and airplanes were added to the arsenal.

“We were very successful in not allowing fires to burn,” said Wirt, who considers the 5,000-acre figure a “phenomenal” statistic that speaks for itself.

“I can’t think of a more difficult place to fight fire, and we did pretty damn good,” said Dave Bunnell, the U.S. Forest Service’s national fire use program manager and a former fire management officer on Montana’s Flathead National Forest. “But the outcome of that is not really what we wanted and certainly not what the landscape required. It was counter, in every regard, to the natural process of dynamic vegetative change through periodic wildland fire disturbances.”

Heavy-handed fire suppression inside and outside wilderness areas came at a cost: tree stands grew thick, decadent and increasingly susceptible to insects, disease and fire. Although logging and other forms of active forest management offered a debatable degree of remedy outside of wilderness, those methods were completely banned inside the wilderness.

“Really the only tool we have at hand to manage vegetation in wilderness is fire,” Wirt said.

But implementing prescribed fires, even in wilderness areas, was a political hot potato. “It was heresy,” Bunnell said.

In 1972, Forest Service land managers took the bold step of allowing a fire to burn in the White Cap Creek area of Idaho and Montana’s Selway-Bitterroot Wilderness. It was the beginning of the wilderness’s fire program. Last July, agency old-timers involved with that decision had a reunion for the thirtieth anniversary of that fire.

Even as fire was reintroduced to the Selway-Bitterroot, it wasn’t until 1981 that a 230-acre fire was allowed to burn in the Cigarette Creek drainage of the Scapegoat Wilderness. And four years later, Bunnell was involved in planning when lightning ignited three fires on Charlotte Peak in the Bob Marshall Wilderness.

Even then, allowing the fire to burn was a tricky proposition that ran counter to societal acceptability and the Forest Service’s firefighting culture, Bunnell said.

After an all-night meeting, managers made the decision to allow the fires to burn. A seventeen-year-old forest covering 5,000 acres on the slopes of Charlotte Peak is what remains today.

“That was a threshold fire. That was a harbinger of future management in the wilderness,” Bunnell said. “On that fire, it was the first time in our history that we had a long-term plan to manage the fire, and second, a public safety plan based on time and predicted spread.”

Just a few years later, the disastrous Canyon Creek Fire clearly illustrated the potential for wilderness fires to exceed their boundaries. As other large wildfires were burning in Montana, the Canyon Creek Fire blew out of the southern end of the Bob Marshall Wilderness, driven by unusual jet stream winds that reached the earth’s surface. The fire raced eastward across the Continental Divide and toward the town of Augusta. Landowners filed up to $5 million in claims against the Forest Service. The fire led to the suspension of the wilderness fire use program for two years.

Bunnell and Wirt said that much has been learned since then, and that all fires that are allowed to burn in the wilderness have to meet specific criteria.

“Some people imagine that we just let any fire go, when in reality we’re suppressing 50 percent of these fires for various reasons,” Wirt said.

If a fire is poised to burn across a large expanse of ground leading to the eastern fringe of the wilderness, it’s usually put out. But if it’s late September or October, it might be allowed to burn. Fires are often allowed to burn if they are surrounded by rocky ridges or areas that have previously burned.

Other factors that come into play include firefighting resources that might not be available for an all-out suppression effort in the wilderness or burning conditions that could be so severe that all fires are extinguished.

As more ground is covered by fire in the wilderness, Bunnell said, it’s easier to manage fires between burned areas, and fire managers like Wirt become better at predicting fire behavior.

Nearly every year since the program was established, there have been at least a few fires burning in the wilderness by late summer.

The results have been impressive, Wirt said, and with each passing fire comes more diversity and stability in the wilderness.

Outfitters and wildlife biologists largely agree that conditions for big game have improved since fire was reintroduced in the wilderness.

Homogeneous, overgrown areas have been replaced with sun-loving shrubs that big game thrive on, such as mountain maple, willow and serviceberry. Many fires have burned at high elevations, priming the ground for whitebark pine, a species that’s been in decline across the western states.

“A picture should be developing from our program of having fires in here for the last twenty or so years,” he said. “It makes you wonder what it would look like otherwise.”