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The spreading epidemic of pine bark beetles

Article by Allen Best

Forests – December 2007 – Colorado Central Magazine

THE BARK BEETLE EPIDEMIC along Interstate 70 and regions northward has received broad attention, and rightly so, with concerns that the outbreak might move south into Central Colorado.

While epidemics have come and gone in decades past, this is unlike anything in recorded history. You get glimpses of it while driving on I-70, but only glimpses. For a truly profound moment, you must leave behind the interstate, drive northward from Silverthorne, then cross Ute Pass into the Williams Fork Valley. As best I can tell, that is ground-zero for the current epidemic.

More than a quarter-century ago I worked in that valley, a winter shoveling snow at the molybdenum mill operated by Amax. I was young then, and could stay up half the night and go climb a mountain the next day. Now, I do neither, and returning there in June, looking at the slopes above the William Fork River, I saw trees that looked like I sometimes feel. Live trees were the exception. Foresters say 90 percent of lodgepole pine will die in this epidemic, and that looks to be the case already in the Williams Fork. The only places of profuse greenness are in those areas of logging operations in recent decades. More commonly the picture is similar to that of a burned forest, but without the charcoal. In short, I saw Colorado not as it used to be, but rather Colorado as it will be.

The landscape is changing profoundly. So are attitudes. Fifteen years ago, the dominant sentiment in ski towns was an almost knee-jerk reaction against all timber sales and, by extension, the U.S. Forest Service. “I’ve read about those guys in Sports Illustrated and what they’re doing on the Tongass Forest in Alaska,” said one of Vail’s more strident speakers at a meeting in 1988.

All timber sales were ugly, and by extension, all trees were beautiful.

Red and dead trees in the Williams Fork Valley
Red and dead trees in the Williams Fork Valley

I remember another incident, from 1996, when the Forest Service proposed to burn the bushes and some trees along Vail’s periphery. This was before the Los Alamos fire in New Mexico in 2000, when a prescribed fire went awry. A distressed homeowner, a transplant from California, said she had moved to Colorado to be next to trees. She wanted no part of this controlled fire. Nor was she alone. The hidden assumption was that today’s scenery would remain forever. Nature was a constant, not a process.

But if forests seemed to change little during the 20th century, they are changing rapidly now. Changes similar to those of northern Colorado are possible, maybe even probable, in the lodgepole forests around Leadville, Salida, and other parts of Central Colorado.

The argument here is that if this great die-off is a more-or-less natural process, it nevertheless provokes a reassessment of our relationship to the landscape.

The first wave of Euro-American settlement during the 19th century mining boom was a simple one of exploitation. That led to the withdrawal of the commons into forest preserves beginning in 1881, and then, in 1905, delegation to the U.S. Forest Service to regulate forest use. After World War II came more changes: the arrival of a well-defined recreation industry, particularly the ski resorts, and then additional layers of environmental laws. This resulted in a fundamentally different way of looking at the forests, as backdrops, in which all efforts to manipulate the forests were viewed skeptically, as the anecdotes from Vail tell us.

That we’ve already reached a new era is told by a postscript from the ski towns. A couple of years ago, a delegation from Vail and other ski towns and resort valleys went to Washington D.C. This time, the locals were pleading with the federal government for money to manage the adjacent forests.

In effect, they were asking for below-cost timber sales. I don’t know if they got any money, but the larger story is clear enough. The federal government cannot possibly become what amounts to a gardener, tending to the vast stands of forests that are the backyard and backdrop in our new settlement of Colorado, the settlement based on æsthetics and not commodity extraction. Who should pay for the management of the forest interface has yet to be worked out. But the potential — only the potential at this time — exists for a different relationship.

How we got here

Forest ecologists say that bark beetles are a fixture of our forests. Colorado has three primary species: the mountain pine beetle; the spruce beetle; and the ips beetle, which depends upon piñon trees. All are active steadily, killing the occasional weakened tree when populations are endemic. The last significant outbreak in the Vail-Granby area was in the early 1980s, but petered out in 1985. The current epidemic is often attributed to a “perfect storm.”

But the contributing factors to this storm vary. One common argument is that the forests of lodgepole pine tend toward an even age, mostly 100 to 125 years, when they’re more susceptible to diseases and bugs. The boilerplate explanation is that the miners, railroad builders, and homesteaders cut trees at a tremendous rate. One estimate of the cut of lodgepole pine in the I-70 corridor counties (Eagle, Summit and Grand) shows 180,000 acres cut in the first decade of the 20th century, a figure barely exceeded for the rest of the century. Also, many accounts point to major forest fires in the 19th century. In some stories, it was the Utes, and in others the finger is pointed at prospectors who wanted to see the rocks underneath without the nuisance of vegetation.

I don’t buy all of this story. First, although you can credit settlers with the pluck, desperation and enterprise needed to denude hillsides without the assistance of chainsaws, why would they bother to remove spindly trees unsuitable for timbers? Or clear-cut distant, dangerously steep slopes for firewood?

I’m also dubious of laying the blame on stand-replacing fires in the 19th century. Denver’s newspapers paid minute attention to the Colorado mountain landscape during the mining era, and I haven’t come across many stories about fires with the magnitude of the Hayman Fire.

Also at issue is the extent to which forests have been logged. Some argue that the epidemic can be explained by the lack of logging. Again, I’m skeptical, for reasons I’ll explain later.

But the most important contributing factor to this “perfect storm” is the warmer and drier weather of the last decade. Much of that decade, including the exceptionally dry year of 2002, has had below-average precipitation. Trees have been weakened, making them more susceptible to bark beetles.

What knocks bark beetles back is extreme cold. A single night of -20°F won’t do it, and probably not even 30° below. It takes sustained cold — some say a week of 40° below — to kill the beetles. A lesser cold spell during November or April will do the same thing. Beetles during mid-winter have an internal anti-freeze that shields them from ordinary cold.

Such cold is rare. We know this anecdotally. Less certain is the empirical evidence. Nolan Doesken, the state climatologist and the chief record-keeper for about 30 years, says long-term and reliable weather records in the Colorado mountains are surprisingly thin. Few recording locations have stayed constant for even 50 years, let alone a century. Often, thermometers have been moved nearer or farther away from buildings. In addition, reservoirs change temperatures, such as those in Gunnison. Still, there’s just enough clear record that Doesken is confident in saying that extreme cold has become far more rare. It was, however, also rare during the 1930s.

Of course, from what I remember of a few nights in Kremmling in the 1970s, there shouldn’t be any pine beetles there, even now. On Jan. 4, 1979, it got to 62° below at Bob’s 66, which matches the state record set some decades before at Taylor Park, north of Gunnison. For a week that winter it rarely got above zero. Weather less gelid than that in Russia turned back both Napoleon and Hitler.

Going to war

The metaphor of war is frequently invoked in discussions of bark beetle epidemics. One such epidemic of spruce beetles traced to a windstorm in 1939 on the Flat Tops, north of Glenwood Springs, prompted a declaration of war by the late 1940s. Some of this came from the U.S. Forest Service, then even more than now a quasi-military outfit. A video produced at the time sounds like a newsreel from the Philippines.

The Denver Post became the chief cheerleader of the war effort. Lumbermen were interviewed to bemoan the loss of valuable resources, while marmots and other critters were reported to be fleeing the scene of destruction. The newspaper castigated any that dared to question the need for federal money. The Forest Service recruited Navajos from the rez and drunks from Denver’s Larimer Street to spray “goop” — a chemical poison — onto the trees. For several years, the war continued, and the Post was exhorting the troops for yet another summer when, in a small story, the newspaper reported a surprise. The beetles had disappeared. It seems that cold temperatures of -50° the previous winter in both Eagle and Kremmling had suppressed the beetles. If not land mines, buckets of the chemical “goop” remained in the forest until just a few years ago. Maybe some still remain.

The current epidemic along the I-70 corridor can be traced to 1996. This time, the debate is more sophisticated. Only once has the Denver Post resorted to trite talk of wars and such. The Forest Service has likewise had a more measured response. Four years ago when I talked to Frank Cross, then the chief bug specialist in the regional office of the Forest Service, he counseled restraint. Telling efforts could be made in special places, such as at ski areas, or near campgrounds, but any effort to ferret out all beetles in the backcountry, he said, was misguided.

Dead lodgepoles with Dillon Reservoir in the background
Dead lodgepoles with Dillon Reservoir in the background

This beetle epidemic has rewritten the rules. In previous epidemics, pesticide liberally splashed on trees protected them. This time there are so many beetles flying every summer that even a small patch of tree missed can be invaded by beetles. Each pair can lay up to 75 eggs between the bark and the tree trunk. Pine beetles are reputed to hit only the older, larger trees, but in fact, some new growth and smaller trees have also been attacked.

Unshackle the professionals

To foresters, the beetle epidemic represents a kind of ironic, bitter-sweet triumph. They were taught in schools that they could manage forests. During the ’90s, they felt spurned, rejected, and disrespected as logging operations fell off sharply. Their message now is that if only the public had allowed them to manage the forest, we would not have the bark beetle epidemic, or at least something well short of its current dimensions. Just let them tend the forest, they seem to say, and it will always be healthy.

Their argument has some merit. The pendulum swung too far during the 1990s. As in the case of the planning commissioner in Vail, every timber sale was the Tongass giveaway. But there’s also plenty of nonsense coming from foresters.

One day in September, at a conference near Winter Park devoted to bark beetles, I listened as a young state forester stood, pointing to a nearby mountain — Big Sheep in those parts, to differentiate it from Little Sheep — and proclaimed that instead of turning red, it could be green, if only the professionals were allowed to have at it and do their jobs.

I questioned him on the point. Nearby Fraser had been a logging town for a century. There were camps everywhere in the woods. After World War II, operations were centralized at sawmills in the nearby towns, Granby and Kremmling. The one in Kremmling, Edward Hines, was operating at full capacity in the 1970s, and at least once I watched the mill manager do his best to bully Forest Service rangers for not offering enough timber.

In 1984, his sawmill was replaced by Louisiana-Pacific, a big outfit based in Portland with a hard reputation, which it fully lived up to. It cut lots of wood, and then blamed the Forest Service for not offering more. It had a new product called Waferwood that glued chips together. The glue had formaldehyde. It came out that L-P personnel were instructed to dismantle the pollution control equipment after the state health inspectors had left. Even Kremmling, with its blue-collar sensibilities, ultimately was happy to see L-P leave. When it did, L-P delivered its pink slips two days before Christmas. The CEO didn’t fly in on his Citation jet to deliver them personally.

I tell this story not to generalize. Not all timber operators were like L-P. But, in fact, the Forest Service “got a lot of the cut out” during the 1970s and even the 1980s. It’s probably fair to say that the lumbermen had some legitimate beefs. In the end, though, the lack of a strong wood-products industry in Colorado says more to the so-so nature of our trees and the flattening world.

Nearly all the sawmills are gone now. A few years ago, the sawmill in South Fork closed. Only one major sawmill, located in Montrose, still operates, taking wood from more than 300 miles away — an astounding investment in diesel fuel for relatively scrawny logs.

Standing there by Big Sheep Mountain that afternoon in September, I asked why it had never been logged. It was public land, outside of wilderness. Three sawmills had been located nearby. Forest Service rangers had even been ordered to “get out the cut.” Yet the trees had been allowed to grow, and were now old and big in an epidemic of beetles that were invading young and thin trees.

The answer, it turns out, was because the slopes were too steep for logging roads. That’s the story in much of Colorado where the bark beetle is now having its way. It was just too steep for logging.

Using the biomass

But there is, in fact, plenty of dead wood standing, with more sure to arrive soon. Within a few years, all of Summit County is likely to look like the Williams Fork Valley where I once worked. There, as well as in Vail and in Grand County, there is much talk about what to do with the wood. For one thing, if you aim to cut down the trees, it’s useful to have a buyer.

The market for old lodgepole pine is relatively thin. Spruce trees on the Flat Tops killed by spruce beetles in 1950 were harvested, for house logs, until just a few years ago. Lodgepole pine, however, have a different fiber. The wood breaks down rapidly, and within five years cannot be used to create two by fours.

Summit County thought about building a biomass burner near county buildings in Frisco, but was told it would cost too much. Such heating systems must be installed initially, not as retrofits. A delegation from Vail visited Austria, the native land of one of its former mayors, and learned about community electricity generation by burning plants. In Walden, a small-scale operation already exists. Mountain Parks Electric is investigating getting part of its electricity from biomass burners, lessening the demand for coal.

One question hanging over all such capital-intensive projects is how long a supply of wood can be guaranteed. Most operators want 20 to 30 years supply of wood. Financiers also will want to know who will buy this product.

In Kremmling, two separate and apparently competitive plans are afoot for pellet mills. But can enough bags be sold at Home Depot to keep both busy? One possibility now being investigated is the idea of creating a large enough burner for a new hotel in Vail to generate a need for pellets by the truckload. Forests along the town’s perimeter are already being thinned. This year, 8,000 trees were removed, and most of them hauled to Kremmling. The majority of cost was borne by Eagle County government, with lesser amounts from the Town of Vail, plus state and federal grants. Vail, year by year, is trying to create a moat of defensible space.

Fear of fire

Fear of fire is propelling much of the excitement. Senator Ken Salazar last December got a huge headline in a Denver newspaper when he likened our beetle-infested forests to a major disaster, labeling them the “Katrina of the West.” It’s a galvanizing phrase, but also misleading. That point was made clear to me last summer when I met with the fire chief in Grand Lake. Located at the west entrance to Rocky Mountain National Park, Grand Lake is still a place of knotty-pine cabins set among the whispering pines — pines now turning red. Across the lake, all of Shadow Mountain is rusty looking. But what distinguishes Grand Lake is that there’s only one way out of the town, out to Highway 34. It’s easy to imagine a giant forest fire raging, flames being pushed by stiff winds from the west, until there is no escape.

I wondered if the prospect of a forest fire kept the fire chief awake at night. No, he said, not really. For a time it bothered him, but now he felt he had done pretty much all he could do. And in a way, he said, all these dead trees didn’t change the story all that much. That comment surprised me. Cops and journalists are ever beckoned by drama. I expected the same from a firefighter.

But his explanation made sense. When a tree died, he said, the red needles on the branches heighten fire risk temporarily, because they can carry a crown fire. After the needles fell, he explained, the fire danger receded for a number of years. Eventually there was a strong likelihood of a major, major fire. But, he added, there had always been a danger. Fires can occur in forests in the right conditions, and although harder to get going, can burn even hotter. So, he concluded, all these beetle-killed trees were just a not-so-subtle reminder to take defensive measures that needed to be taken anyway.

So, this is probably not the “Katrina of the West” that Salazar described, although it could be, if continued drought exacerbates the situation. Scientists refused to attribute Katrina to global warming, but instead concluded it was part of natural variability. And scientists, including a team of forest ecologists headed by W.H. Romme of Colorado State University have argued that large fires on the Colorado landscape should not be viewed as unusual, even if they do not occur often.

“… we should expect large fires in the lodgepole pine in the future, and these future large fires should not be viewed as abnormal from an ecological standpoint,” they say in a paper called “Recent Forest Insect Outbreaks and Fire Risk in Colorado Forests: A Brief Synthesis of Relevant Research.” “The key point about lodgepole pine forests is that they were dense and burned infrequently historically, and they are dense and burn infrequently today.”

So big beetle outbreaks, if uncommon, are not unnatural. Ditto for big fires in the lodgepole forests of the high country. In fact, the two are not necessarily related, say Romme and his associates. In other words, just because a forest is full of standing dead does not mean there will be a fire roaring through it. Yet it may be a catalyst for action. I have long been struck by the artificiality of the boundary lines in places like Vail and Summit County. On one side is designated wilderness and, on the other, mountain-style suburban and exurban living. The same thing seems to be happening in the upper Arkansas Valley. Ultimately, there needs to be greater responsibility assumed by local governments for their permissive land-use patterns. The Forest Service model needs to be re-examined.

But that is perhaps another essay.


In all this, I am struck by the fact you just can’t yank words off the shelf such as “war” and “victim” and “natural.” What words are used ultimately say as much about the perception as they do about the subject being observed.

Romme, et al., make much the same point. “From a purely ecological standpoint, dead and drying trees do not necessarily represent poor ‘forest health,'” they write. “They may instead reflect a natural process of forest renewal.”

During September, while at the bark beetle conference, I drove to a dude ranch and cross-country ski center located in a secluded valley between Granby and Winter Park. From the valley’s sagebrush flats a forest sweeps up to tundra and Continental Divide, beyond which is a spire of rocks, the namesake for the Devil’s Thumb Ranch.

It’s a beautiful setting made more pleasing yet at sunset when the sun ray’s bend over the horizon, tinting the snow first orange and then red in a phenomenon called alpenglow. There was no snow when I visited, but the trees, thousands and thousands of them, nearly all rust red with dead needles, lent the feel of alpenglow. These dying trees, I thought to myself, are they not a beautiful sight?

Allen Best covers forests, resort towns, and natural-resource issues from his home in Arvada.