In the summer of 1879, the largest wildfire in Colorado history at the time tore through 26,000 acres of rugged forest about eight miles south of Silverton and presaged a vast shift in its landscape.

Laying waste to the coniferous forests in its path, the Lime Creek Fire opened the door for huge stands of brilliant green aspens to move in and replace their spruce-fir counterparts.

Today, those stands continue to color the mountainsides south of Molas Pass, and offer a preview of what shape the Cimarron Range might take in the aftermath of the Gold Mountain Fire.

The Lime Creek Fire casts yet another long shadow — it was, by most accounts, one of the last great subalpine fires on the west side of the San Juans before the modern era. Reigning as the largest fire in state history for more than a century, it now doesn’t even crack the top 20.

In interviews with the Plaindealer, experts in fire ecology said the forests the Gold Mountain Fire burned in June and July likely haven’t seen fire not just in generations, but in centuries, tracking with the 100- to 300-year fire cycle of high-elevation conifer forests.

But while in one sense, the forests of Ouray County were due for a big burn, climate change and an all-timer of a drought also conspired to prime the Uncompahgre Wilderness for a fast-moving fire that appears to have topped out at nearly 40,000 acres and as of this week, has cost over $65 million to fight.

“We’re looking at a hot and dry year that’s already on top of a warming and drying trend,” said Jonathan Coop, professor of environment and sustainability at Western Colorado University. “These are the kinds of conditions that allow these systems to burn.”

Ghosts of fires past

In mid-July, Mike Smith — who was then the incident commander of the Gold Mountain Fire — listed the lack of previous fires in the forest as a challenge for his crew. The forests around Ouray hadn’t burned in hundreds of years, allowing fuels to build up and fire to tear through them at blistering speeds.

How, then, are researchers able to date forest fires which occurred well before settlers arrived and began writing them down?

“We’re talking about the absence of evidence to the contrary,” Coop said.

Unlike lower elevation forests filled with fire-resistant species like Ponderosa pines, spruce-fir forests have almost no natural resistance to fire, experts said. Though they’re typically more insulated from flame by the presence of snow and moisture during most of the year, when they go, they go.

“As you move up to spruce and fir, all the way up to the tree line, fire is very rare,” said Deborah Kennard, an environmental science and technology professor at Colorado Mesa University. “And when it burns, it kills everything.”

Thus in those forests, the simplest way to date their most recent fires is by taking core samples of the oldest trees around, with the assumption they sprouted not long after the last big blaze. Jesse Young, a researcher with the U.S. Forest Service’s Rocky Mountain Research Station in Fort Collins, said other clues can come from the bottom of undisturbed alpine lakes by examining sediment layers, or fallen trees preserved beneath the waters.

“Once you get up to these higher elevation spruce-fir forests … there’s really no evidence of fire scars, if you will, to kind of go back and date everything,” Young said.

In spite of those methods, the date of the last major fire in Ouray County’s high mountains remains something of a mystery. Chris Guiterman, a researcher at the University of Colorado Boulder, has co-led a national project to compile tree ring burn scars from hundreds of sites across North America. But the database includes only a handful of sites in the upper reaches of the San Juans.

The challenge for researchers, Guiterman said, is that fire-resistant Ponderosa pines can contain in their rings the story of dozens of fires. Samples from dozens of spruce and fir trees might be required to date a single blaze.

Ouray City Councilor Jenny Hart, an elementary school history teacher for 27 years in the city, said the written record of the area bears out the notion that the Gold Mountain Fire is likely the area’s first major blaze since white settlers arrived in the 1870s.

“We don’t have stories of fire in our history. Individual buildings in this community have burned, and there are stories around that. But we have no forest fire stories. We have floods. We have avalanches. We have all these big things,” Hart said.

Hart continued, “But people are [saying] there’s not been a fire in 50 years, and I’m like, no, no, you don’t understand — it’s way more than 50.”

Piling the tinder

In other parts of the West, an accumulation of fire fuels has built up over decades thanks to the profound ecological influence of settlement and development. By the modern era, experts told the Plaindealer, Native Americans who often conducted their own prescribed burns had been forcibly removed, while decades of aggressive fire suppression strategies created a tinderbox of brush, trees and debris.

But while the Cimarrons were likewise primed for burning by this summer, those conditions likely owed less to human land management than a perfect storm of the forests’ age and Colorado’s worst drought in modern history.

Young, of the Forest Service, said most of the Cimarrons’ interior “is just so inaccessible that it probably has not really been manipulated by our post-colonial, but pre-modern era logging and stuff like that.”

Instead, an ongoing pattern of warming and drying in the region spurred by climate change is producing ever greater fire risk in mountainous terrain. A 2021 study found that fires in high-elevation Rocky Mountain forests are now burning more frequently than at any time in the last 2,000 years, calling 21st century fire behavior “unprecedented in the past two millenia.”

“At that elevation, it’s climate,” said Colorado Mesa’s Kennard.

“Usually those forests stay too wet during the summer, and nothing can catch on fire if it’s too wet,” Kennard said. “Now with climate change, snow is melting off earlier. It’s coming later. It’s hotter, so there’s more evaporation, and those fuels are getting dry enough that they can ignite.”

While widespread beetle kill may appear to be a tinderbox waiting to burn, experts said that stands of dead trees haven’t necessarily correlated to more intense blazes. Camille Stevens-Rumman, a professor of forest and rangeland stewardship at Colorado State University, said the greatest risk in beetle-stricken forests comes during the initial die-off period when dry, dead needles remain on trees.

“For that one or two years, there’s a potential increase in intensity because of all of those dead needles. But then once they fall to the ground, you actually don’t have as much connectivity in the canopy,” she said, in some cases slowing the spread of fire.

Several researchers also said that logging the upper reaches of the San Juans would likely do little to decrease their fire risk, pointing to the above-treeline fire activity of 2020’s East Troublesome and Cameron Peak fires. The 193,812acre East Troublesome Fire, the second- largest in state history, managed to jump across the Continental Divide.

“We’ve had in Grand Junction many fires that have jumped across the Colorado River, and if 70 feet of water is not a good fire break, certainly logging is not going to create a good fire break,” Kennard said, adding that given spruce and fir’s inability to withstand fire, “it doesn’t matter if you thin the forest.”

Said Stevens-Rumman, “I don’t really want to see our forests turn into [ones] that could actually withstand a fire like that, if the Continental Divide can’t. We’re talking about an almost unvegetated area, and the fire was still able to get over it.”

“Are we going to turn all of our forests into a parking lot?” she added. “That’s not reasonable.”

‘Winners and losers’

As in the aftermath of the Lime Creek Fire nearly 150 years ago, experts agreed that one species in particular is likely poised to come out of Gold Mountain’s ashes with a head start.

“ Anywhere there was aspen on those landscapes,” Coop said. “Aspen will expand.”

Spreading via their root systems as well as airborne seeds floating on the wind, aspen sprouts can begin to pop up almost as soon as the soil has cooled. And they grow far faster than their coniferous counterparts; Kennard said saplings could be waist-high by next summer.

Spruce and fir, meanwhile, may take decades to upwards of a century to reach a mature forest, particularly if older, seed-bearing trees have been wiped out.

“As far as the ecosystem goes, there’s winners and losers,” Coop said. “Someone’s going to lose their place, and someone else is going to move in.”

While researchers haven’t yet been able to examine the Gold Mountain burn scar firsthand, the Forest Service’s Young said from his conversations with personnel on scene that the patchy, “mosaic” burn pattern of the fire could be promising for the Cimarrons’ rejuvenation.

“It sounds like there [were] some nice mixed effects up there, and [the fire was] ultimately probably resetting the system quite nicely — with the assumption, of course, that now we can ride out another 100, 200 years and still be within that natural fire return interval,” Young said.

Across Ouray County and the San Juans, however, acre after acre of alpine forest stretches out that hasn’t seen fire in generations.

“Increasingly hot, dry conditions [are] just setting up our forests for more fire,” Stevens-Rumman said.

As Coop put it, “The big picture is we’re on an upward trend for fire. I work on this stuff, and we analyze this data, and it’s remarkable how closely fire activity tracks climate in spite of all the sort of randomness of where lightning occurs or where somebody lights a spark for whatever reason.”

“The fact is,” he continued, “there’s this very strong relationship, and there are very strong trends that all point to, we’re going to see more — a lot more — of this in the future.” Chart Riggall is a journalist with Report for America, a nonprofit program that helps boost reporting resources in underserved areas. He’s also part of the Western Environmental Reporting Collaborative, a partnership between Report for America, High Country News and local news organizations across the West.