As flames from the Castle Rock Fire swept over Warm Springs Ridge and started backing down into upper Adams Gulch last summer, it looked as if the popular hiking and mountain biking destination would end up a blackened shadow of its former self.
Raging for 20 days, the lightning-caused blaze blanketed the northwest-trending valley in a heavy cloud of inky-black smoke for days on end. Only after darkness fell could people really see into Adams Gulch, when the gleam from torching trees and burning undergrowth pierced the smoke and cast an eerie red, orange and yellow glow across the nighttime sky.
Locals could have been forgiven for fearing they were losing one of the Wood River Valley's most popular recreational destinations.
But Mother Nature apparently had a few surprises up her sleeve. First was the extent of the burning in Adams Gulch. When the smoke cloud finally lifted and the fires flickered out in early September, views showed not a blackened wasteland, but a mosaic of burned timber and range interspersed with what looked to be even more unburned forest and grassland.
Assessments conducted within the fire perimeter after last fall determined the majority of the nearly 50,000-acre fire zone—about 63 percent—burned only at moderate or low intensity. Just 19 percent burned at what fire managers consider severe intensity—in places like Rooks Creek, Red Warrior Creek and Lodgepole Gulch—while the remaining 18 percent saw no fire activity.
Last winter's snows erased views of the canyon's blackened areas for more than six months, except for the needle-straight snags poking out of the continuos blanket of white.
Followed by a cool, wet spring that didn't break until well into June and a flush of nutrients released by the fire into the soil, Adams Gulch and the rest of the fire area were primed for an explosion of regrowth.
Walking along one of the many hiking trails that winds up Adams Gulch on Wednesday, Ketchum District Ranger Kurt Nelson paused next to a lush patch of four-foot tall quaking aspen shoots surrounding a dead tree trunk. Looking up, Nelson pointed to similar bursts of green aspen dotting nearby south-facing hillsides.
"People thought this area would be a total disaster," he said.
That's proven not to be the case. Anywhere one goes in Adams Gulch this summer, signs like these point to an amazing reemergence of plant life only a year after the blaze was contained. In many mature aspen groves on hillsides and valley bottoms that saw burning, impenetrable thickets of three- to six-foot high aspens create a dense blanket of new growth.
Elsewhere, short circles of green include new bitterbrush, while four-foot tall wispy willow bushes have already brought a bit of riparian greenery back to the narrow creek bottom and flat benches nearby. Earlier this summer, many local hillsides were treated to uninterrupted blankets of yellow from flowering arrowleaf balsamroot that some locals said was the best bloom they had witnessed in decades.
Nelson seems particularly pleased with the dramatic comeback by aspen. Forest managers have voiced concerns about declines in the valuable tree species throughout the West in recent years, and have been studying ways to revitalize aspen stands.
Much of the aspen mortality is attributed to the absence of wildfire, due to fire suppression. Forest managers say aspens require fire to avoid being overtaken by conifers, which foresters refer to as climax tree species.
"They need that disturbance regime," said Sawtooth National Forest botanist Kim Pierson, who accompanied Nelson for the walk through Adams Gulch.
In the portions of the eastern Smoky Mountains that burned last summer, the Castle Rock Fire may well have been just what aspen stands were waiting for. Holding a stem from one of the new aspen shoots, Pierson pointed to broad, three- to four-inch leaves. The purpose of these large leaves is to catch more sunlight to aid in new growth.
"They're just going gangbusters," she said.
In many aspen-dominated locations around the West—perhaps most notably in Colorado—aging aspen forests are at least 80 years old. Forest Service data indicate aspens generally live to an age of 100, and to 200 in rare cases.
A Forest Service report titled "What's Happening in Colorado's Aspen Forests?" says the gradual evolution of aspen forests in the state changed dramatically in recent years, with widespread deaths of old aspen trees. Though the researchers say the loss of these older trees doesn't mean aspen forests will disappear—some stands have younger trees that will survive and some are sending up new shoots—they do note widespread concern among foresters about the future of aspen forests.
The researchers say overbrowsing by livestock and large herds of elk and deer is contributing to a lack of new shoots' or suckers' surviving to become fully grown trees. Here, fire or mechanical disturbance may be the key.
"We know that cutting or burning healthy, mature aspen trees leads to such a proliferation of suckers that browsing pressures are less likely to prevent regeneration of the forest," the researchers state.
In the near term—perhaps within several decades—local forest managers expect to see an increase in aspen groves on the Sawtooth National Forest. Pointing to a visible swath of mature aspen that adorns Warm Springs ridge just northwest of Ketchum, Nelson said new aspen shoots may begin to extend into a stand of blackened Douglas fir trees just up the hill.
That part of the Warm Springs ridge last burned about 100 years ago, when the fire created a mosaic of trees of varying age classes. Nelson said last year's fire will not only aid in new aspen growth on the ridge, but further diversify the forest.
"We'll see more of that differing age class," he said.
Kurt Nelson, Ketchum District Ranger for the Sawtooth National Forest, holds up a stem from a willow bush burned to the ground during last summer’s Castle Rock Fire. Throughout the entire 48,520-acre fire area, aspens, bitterbrush, willows and other plant life are exploding in a profusion of regrowth just a year after the flames flickered out. Photo by Jason Kauffman
