August 20, 1988, was not a very good day in Yellowstone National Park. At least not for the 2,000 firefighters that were trying in vain to get a handle on the wildfires burning during the park’s biggest fire season in recorded history. Since June 23, eight major fires had burned across 282,000 acres. But on “Black Saturday,” as it would become known, a dry cold front brought steady 40 mile-per-hour winds with gusts ripping up to 70 mph. Firefighters could only scramble out of the way as flames roared across the landscape, burning 160,000 acres in 24 hours—nearly five times what had burned in the park during the previous 16 years combined.

	BLACK SATURDAY: More than 160,000 acres of Yellowstone burned in just 24 hours on August 20, 1988. That’s more than in the previous 24 years. All told, more than a third of the park burned that summer. Such statistics fueled the mistaken notion that Yellowstone would never recover. (photo by Becky Blankenship)

But summer rains didn’t come in 1988. After a wetter than average April and May, no moisture to speak of fell in June, July and August. Day after day of hot, dry wind desiccated the Yellowstone Plateau. A picnic table typically has a higher moisture content than the park’s grasses and trees held that summer. Dry lightning and careless humans touched off multiple blazes. Park officials let 8,600 acres burn according to policy until July 21, when they decided conditions were too extreme and ordered all existing and new fires suppressed.

But Mother Nature was now clearly at the helm. Day after day, high winds propelled flames up to 200 feet high through the park’s ubiquitous lodgepole pine forests, tossing embers a mile or more ahead of the main fire and over natural and man-made fire breaks, sparking new blazes. Big fires joined together into conflagrations. Firefighters were forced to go from attempting to corral the flames behind fire lines to solely protecting human lives and property.

Yellowstone’s fires raged until September 11, when the first significant moisture since Memorial Day fell in the park. Fall rains, snow and cooler temperatures finally snuffed out the flames by late October. By then, 25,000 firefighters had hand dug more than 850 miles of fire line. Airtanker and helicopter pilots had logged over 18,000 hours dropping 1.4 million gallons of retardant and 10 million gallons of water. The single largest firefighting campaign in U.S. history to date cost $120 million ($161 million in 2008 dollars). Despite that effort, more than a third of the park burned.

From a human perspective, the summer of ‘88 in Yellowstone was one of chaos, awe and concern. For most of the park’s elk herd, which hovered around 30,000 head at the time, it was just another season on the Yellowstone Plateau.

“Most people have the movie Bambi ingrained in their minds, with animals hysterically fleeing the flaming front of the fire, but it wasn’t like that,” says Roy Renkin, a 29­­-year park researcher who was able to observe elk and bison behavior from the air during daily fire-mapping flights. “When a fire front approached, they’d just move out into a big open area, and nonchalantly wait it out. They’d mill around, chew cud, do whatever until the fire front passed them by. What was interesting was that many of them would then head right into those freshly blackened areas to have a look around.”

Surprisingly, with 30,000 head of elk in the park, mortality surveys in the fall of ‘88 found less than 300 elk died as a direct result of the fires. Most of the carcasses—230—were found trapped in a box canyon that had been burned over. Necropsies showed the majority died from suffocation. Only a handful were burned alive. Along with these elk, researchers accounted for nine bison, four mule deer, two moose, six black bears and one grizzly killed either by smoke inhalation or flames. Creatures that could fly or swim relatively long distances, take cover underground, or outrun the flames suffered remarkably light losses. Slower-moving creatures like porcupines, as well as innumerable small rodents like squirrels and mice, perished in the flames. Those that didn’t die directly from the fires were easy pickings for hawks and other predators that flocked to the burned areas hunting critters no longer shielded by cover.

	NEEDY SEEDS: Like much of the West, Yellowstone is an ecotype that depends on flames to spawn renewal. In fact, the cones of the lodgepole pines that cover much of the park require fire to release their seeds. (photo by Lance Beeny)

Despain had devoted the previous several years to studying the park’s fire history, including analyzing tree rings to determine the ages of different stands of lodgepole pine, which blanket nearly 80 percent of the park. He found big stands of trees that were all around 130 years old, others that were 240 years old. The evidence suggested that large-scale, stand-replacing fires swept through Yellowstone every one to three centuries.

“I wasn’t too concerned about the park being destroyed by the fires in 1988,” Despain says. “I’d seen the regrowth from those big fires, and from other crown fires that had burned throughout recorded history. What did surprise me that year, however, was that it just never quit. There was one old stand I knew of that had most likely been burned by a single fire that covered about 40,000 acres. That’s the scale I had in mind prior to ’88.”

Despain says no one could have predicted the summer’s fires would end up burning with such enormity and intensity. Politicians and the media heaped harsh criticism on park officials for their natural burn policy (dubbed the “let-burn policy”), and for not jumping on the fires sooner. But Despain and most other fire scientists still feel that the extreme and unpredictable weather conditions—which confounded even computer models designed to predict fire behavior—would have prevented humans from controlling the fires regardless of when suppression efforts started or what methods were used. Mother Nature was in control from at least mid-July until heavy snow fell in late October.

Media coverage coming out of Yellowstone that summer was long on sensationalism, short on science. Scenes of 30,000-foot smoke columns, roaring walls of flame and blackened moonscapes blanketed the front pages of newspapers and flashed across TV screens daily. Much of the time they were accompanied by adjectives like disaster, decimated, never going to recover.

These gloomy reports frustrated biologists and park officials alike. At the height of the season, Yellowstone superintendent Robert Barbee emphatically told the press, “Fire is a stimulant and is as important to the ecosystem as sunshine and rain. This is not destruction—period!” But many refused to believe. Offers to help restore Yellowstone poured in from all over. Children from a grade school in Missouri sent a box of acorns they had collected in their playground and New Jersey’s governor pledged 2,000 seedlings to help reforest burned areas.

Preliminary reports indicated 1.1 million acres, or half the park, had burned. But satellite images and mapping flights found this number represented the perimeter of burned area. The fires had hopscotched across the landscape, creating a jigsaw puzzle of black, brown and green depending on where and how hot the fires burned. Turned out 790,000 acres had truly burned. Of that area, about half experienced severe crown fires that raced through the treetops, leaving blackened matchsticks standing in their wake and gutting the forest floor of duff. In other areas, flames burned closer to the ground but were still hot enough to kill trees in their path. Many of these blackened areas were fringed with brown, where the heat had only singed the needles but still killed the trees. Adjacent to the brown were areas where the fire had just burned small pockets of duff, sparing the trees altogether.

According to Despain, less than 1 percent of the burned area experienced temperatures hot enough to remove the organic matter from the mineral soil. “On the other 99 percent, even though you had a layer of ash that looked like the bottom of a barbeque pit, the killing temperatures only reached three-quarters of an inch on average into the soil, leaving most roots and bulbs intact.” In fact, he says, it wasn’t unusual to see grasses and forbs sprouting and flowering in burned areas within 10 to 20 days after the rains came in September.

	WINTERKILL, NOT FIREKILL: Having shed its antlers, this bull was more likely a victim of snow and cold than flames and heat. Ninety-nine percent of the park’s elk herd survived the fires of 1988, sometimes even foraying out to explore the blackened landscape while it was still smoking. Just as with this bull, though, their fate would be colored white. Thousands of elk starved during the harsh winter that followed. (photo by michaelfrancisphoto.com)

Fire is the key that unlocks lodgepole pines’ serotinous cones. These cones are sealed shut with a hard, waxy substance. They require heat—113 to 140 degrees Fahrenheit—to soften the wax so they can open and release seeds.

John Varley, who was Yellowstone chief of research at the time, says 32 miles of bulldozed fire lines probably left more of a negative impact on the land than did the fires themselves. “Despite the public’s concern over rehabilitating the park, we did very little of that,” he says. “We seeded bulldozer lines and laid down some fire-killed trees on steep slopes in the Absaroka Range to slow erosion. But we did no reseeding or replanting in the burned forests. We decided to let nature take care of itself.”

And so it has. In what many viewed as a total loss, scientists found a once-in-a-lifetime opportunity. They flocked to study the fires’ effects on everything from invertebrates to elk, from soil quality to stream morphology, and from public attitudes to economics. More than 250 research projects—including a number funded by a young Rocky Mountain Elk Foundation—launched in the first six months after the fires.

Coming into the summer of 1988, Yellowstone’s elk were fat, happy and aging gracefully. Nearly a decade of mild winters and rainy summers combined to produce ample forage that kept the herds well fed. Calf recruitment had been strong throughout the ‘80s, spiking up to 90 percent in some years. The famed northern herd numbered almost 19,000. It was far and away the highest population since biologists began making accurate winter counts and almost double the 75-year average.

Then a third of the park burned and what remained was hammered by record-dry conditions. The grass that was left had the nutritional equivalent of cardboard. So a lot of elk went into the winter in less than optimum condition. And here came a real winter. Deep snows and severe cold sapped the elk’s meager fat reserves. Elk ate whatever they could find hovering over the snow that winter: sagebrush, aspen bark, branches, needles and mosses growing on trees. In the Madison River drainage, elk were observed peeling and eating great strips of burned lodgepole bark—a phenomenon not previously reported. Chemical analyses of charred bark detected no substantial increases in its nutritional value. What was the sudden attraction? Researchers concluded that elk were eating burned bark simply because they could: it was everywhere and took very little energy to wolf down in generous quantities.

Elk started dying on the northern range in December. By February, they were “dropping like flies,” says park researcher Roy Renkin. “I recall one day in late February during that last cold snap, I was driving to work from Gardiner to Mammoth, a five mile stretch of road, and I counted 11 fresh elk carcasses down along the Gardiner River. Even as a biologist it was eye-opening to see that. I’d never experienced a die-off to that degree.”

Once again the Park Service was under fire, this time for not feeding the starving elk.

	PRIMED AND READY: As decrepit as a forest looks just after a big burn, it can be hard to appreciate the smorgasbord of seeds that lies in wait just beneath the ash. (photo by Becky Blankenship)

Renkin says people who understood the larger intentions for the elk population as a whole accepted the decision. “But when people look at an individual elk and they see how emaciated it is, it becomes an emotional response to want to help that elk out.”

Watching thousands of elk starve, the Elk Foundation wanted to help, too, but fully supported the agencies’ decision not to feed. Instead, the foundation sought a more enduring solution. Yellowstone offers some of the finest summer range imaginable for elk, but it’s a high, harsh place come winter. In a government study published in 1917, Henry S. Graves, forester for the U.S. Forest Service and E.W. Nelson, chief of the Bureau of Biological Survey reported:

“Unfortunately, when these reservations [Yellowstone National Park and surrounding national forests] were established, and during the early years of their existence, the needs of winter range for the elk were not given consideration … Areas which are essential to the maintenance of the elk herds were not withheld from entry under the general land laws and have become private holdings. The key to the situation is the area lying north of Yellowstone National Park, 40,000 acres of which lie between the boundaries of the Absaroka and Gallatin Forests, extending north 15 miles along the Yellowstone River from the town of Gardiner to Yankee Jim Canyon … Ownership and control of this area by the public is essential to the future of the northern elk herd.”

Graves and Nelson proposed that the government acquire all this land at a cost of $500,000. Their assessment was dead-on, but the solution didn’t come to pass. Over the next 70 years the land was settled with cattle ranches, dude ranches and the sprawling world headquarters of the Church Universal and Triumphant. The Elk Foundation, just 4 years old in 1988, decided seven decades of inaction was long enough. The foundation and its partners at the agencies began seeking out landowners willing to donate conservation easements or sell their land. By the end of 1989, the Elk Foundation had completed seven acquisitions and easements that permanently secured 7,000 acres of the most coveted winter range. In the 19 years since, the foundation has permanently protected another 25,259 acres of vital winter range north of the park.

Prior to the winter of 1988, only 15 percent of the park’s elk migrated north of the park most years. But that year a full half the population came north. Thanks to work begun by the Elk Foundation on the heels of the fires in ‘88, the elk had somewhere to go. Mark Boyce, a professor at the University of Alberta who has studied the habits and habitats of Yellowstone’s elk for more than 30 years says, “The timing was good. Securing those parcels of land just opened things up for elk. That winter more elk than we’d ever seen before started using winter ranges north of the park, and they’ve been using them pretty much continuously since then.” 
 

	FULL THROTTLE: Yellowstone’s fire-dependant species such as lodgepole pine had an absolute field day in the years following 1988, with some stands getting their first chance to regenerate after a 240-year wait.  (photo by Jeff Henry/yellowstonephoto.com)

“It was just a devastating effect on elk that year,” says Boyce. “It sort of reset everything, knocked them back down. Then immediately things greened up that next year, and elk were in fat city.”

Within two years, the northern herd bounced back by 50 percent. By 1995, it had exploded to more than 19,000.
 
John Varley likens the nutritional value of plants before and after fire to eating a salad made of iceberg lettuce versus one created with mixed organic greens. “For the first couple years, annuals in the grasslands and shrublands are more abundant and packed full of vitamins and minerals. It’s just gold,” he says. “After four or five years, this influx diminishes and plants return to their pre-burn condition.”
Lodgepole pines typically grow in dense stands, the canopy shading out sunlight-hungry grasses and wildflowers. But after a fire, sunlight pours in and ash releases phosphates and calcium into the soil. Add a little moisture, and the seeds, bulbs and stems that have been biding their time for decades—even centuries—take root.

A magenta blanket of fireweed seemed to cover the park for the next few years, but other flowering plants such as elk sedge, showy aster, pinegrass and lupine also flourished. Dragon’s head and Ceanothus (snowbush)—rare in Yellowstone—were more prolific post-fire. A few species, including Bicknell’s geranium and mountain hollyhock, made their first appearance in the park—at least in modern times—after the fires.

	LAND OF FIRE, LAND OF ELK: “Elk appear to be using the landscape more completely today than they were before 1988,” says professor Mark Boyce, who has spent more than 30 years studying the habits and habitats of Yellowstone’s elk. Elk have proven themselves superbly suited to Yellowstone’s ever-changing landscape. (photo by David Irwin)

“Seed establishment requirements are quite stringent,” Despain says. They need major doses of both moisture and sunlight for their first two weeks of life. The fires knocked back competing vegetation and burned off the duff, creating an ideal seedbed. Abundant moisture the first year following the fires helped aspen seedlings take off in habitats all over the park, but they seemed to do best in old bogs or pothole lakes where the deep organic matter had been burned to ashes. Many new aspen seedlings produced a root sucker the second year. True to form, elk nipped back aspen suckers and seedlings as fast as they came up. Many died off, but new stands took hold in some locations. “These get browsed back every year by elk, but they’re still there,” Despain says.
 
Lodgepoles, of course, went hog wild. Among the most fire resilient of all pine species, they depend on periodic fires to regenerate, and typically grow in thick stands where all the trees are the same age. Individual trees shed their lower branches every year, which protects them from ground fires. When a stand reaches about 100 years old, shade-tolerant spruce and fir begin sprouting on the forest floor. These species will eventually overtake lodgepole pine, until another large crown fire sweeps through the stand every couple hundred years. Not only is fire critical to maintaining Yellowstone’s lodgepoles, it’s also vital to creating stands of different ages. A diversity of young, middle-aged and old forests is crucial to supporting the wide array of plants and wildlife that call the park home.

Twenty years after the fires, some lodgepole saplings now stand 20 feet tall. The size of the young lodgepoles depends largely on soil type, but the density of these new stands largely reflects the density of the old stands pre-fire, a trend that impresses Bill Romme, an ecologist at Colorado State University who has researched the park’s forests for more than two decades. “That was one of the really striking things. The overall patterns did not change very much. In other words, where dense lodgepole pine forests burned, a new, dense lodgepole forest is in the making. Where an open forest with a low tree density burned, there is a low-density forest redeveloping. Where a meadow burned adjacent to a forest, the boundary between the meadow and the forest is hardly changed at all.”

This phenomenon is echoed in habitats throughout the park. Meadows have come back as meadows; riparian zones have come back as riparian zones; the expansive sagebrush-grasslands of the northern range have come back as, you guessed it, sagebrush-grasslands.

Many of the dire predictions of seared wastelands devoid of life, severe erosion and streams choked with sediment did not come to pass. In a few instances, fire retardant got into streams and killed some fish. But for the most part, the fires were a boon.

“If you’re a trout living in a stream at 8,500 feet, you’re not sorry to see those trees go,” says Varley. “When the forest opens up, sunshine warms the waters a bit, encouraging more algae and aquatic plants to grow, which tumbles right down through the food chain from protozoans to invertebrates to fish.” Burned trees create downed trees that create splash pools that create spawning habitat and protective cover.

Despain adds that studies indicate that for about five years after the fires—or until streamside vegetation began shading the water again—trout fingerlings entering Yellowstone Lake from tributaries that had burned were slightly larger than those coming from tributaries that hadn’t.

Another concern that has not played out is related to the loss of 25 percent of the park’s whitebark pine to fire. This tree, which grows in the high country along timberline, produces seeds which are a crucial food source for Yellowstone’s grizzly bear population, as well as Clark’s nutcrackers, red squirrels, chipmunks and deer mice. Studies indicate that grizzlies made up the difference by shifting to other food sources. And whitebark pines are reestablishing themselves, thanks in part to the work of nutcrackers and squirrels who cache seeds in the soil. Unfortunately, the future of whitebark pines is now very much clouded by the scourge of blister rust sweeping the West, but that’s unrelated to the fires.

Thanks to high litter sizes and low reproduction age, populations of rodents that suffered significant mortality during and immediately after the fires were back to pre-fire numbers within a few years. Fire-dependent species like black-backed woodpeckers—rare to Yellowstone—flocked to the park immediately after the fires to feast on the throngs of bark beetles that had invaded the burned trees. When the snags began losing their bark, the woodpeckers moved on, but the excavations they left behind still benefit cavity nesters like mountain bluebirds and swallows.

And when those snags eventually blow over, they’ll provide another long-lasting benefit to the park’s ecosystem as what scientists call “coarse woody debris.” Millions of trees died in the ’88 fires. Many snags have since fallen, but many still stand. Researchers predict that in another decade, 90 percent of the snags will have fallen, generating an estimated 25 million metric tons of debris on forest floors across Yellowstone—comparable to the weight of 78.5 million bull elk. Over the next century these logs will slowly decompose. Fungi and bacteria will encourage the rotting wood to release nutrients and organic acids into the soil for neighboring plants. Ants, beetles and other insects will move in, providing a feast for everything from grizzlies to flickers.

And what about the elk? “It was very enlightening to see that degree of die-off, and then experience how rapidly and vigorously the northern herd responded to that whole event,” says Roy Renkin. “It told me that the population is very healthy and resilient to disturbances like drought, fire and severe winters.”

Severe winters in both 1995-96 and 1996-97, high hunter harvest and the reintroduction of gray wolves combined to bring the northern herd’s population down to between 8,000 and 10,000 animals, where it remains today.

“Wolves almost surely are contributing to keeping the numbers down,” Boyce says. “One thing that strikes me about the elk counts since 1997 is they don’t vary much. Before wolves were reintroduced, the variability in the elk population was enormous. We predicted in our models prior to wolf reintroduction that wolf predation would help stabilize elk numbers, reduce the amount of variability in the population size you get from year to year, and that certainly seems to have held up. I think it’s quite certain that the extent of overwinter mortality we saw in ’88-’89 will never be as great now that we have wolves in the system.”

How are the fires affecting elk in Yellowstone today? “Elk appear to be using the landscape more completely today than they were before 1988,” Boyce says. “There are places that are still greatly enhanced as habitat for elk as a consequence of the fires. The young conifer forests continue to grow abundant grasses and forbs that attract elk in the summer.”

In 1992, the park revised its fire policy to include stricter guidelines on where and how big naturally occurring fires would be allowed to burn. That fire will visit Yellowstone again is a given. Most experts agree it will take a century or more before the Yellowstone landscape looks as it did to those of us who visited the park before 1988. Then it will be time for another landscape-scale event. But the park’s habitats, animals and waterways are rejuvenated and well on their way toward restoring themselves as they were before the fires.

“Fire causes a dramatic, immediate change in age of the forest. Instead of being a 100- or 250-year-old forest, the burned forests are a year old after the fires,” Despain says. “But the same species that were in the forest are growing there. The biomass changes, but the species list just doesn’t change much.”

John Varley agrees. “The longer I go back there, the more insignificant those fires become to nature. I have the strong impression that it was just like a hiccup to a landscape like that. It seemed to deal with it with ease, as if it’s no big deal. Everything put itself back together,” he says. “It reordered the proportions of certain species, but it didn’t put anything into jeopardy. There’s reason to trust in Mother Nature, because she never destroys herself.”