When naturalists first hiked through Glacier National Park more than a century ago, 150 glaciers graced its high cliffs and jagged peaks. Today there are 35. The cold slivers that remain are disintegrating so fast that scientists estimate the park will have no glaciers in 30 years.
Boulder Glacier, once massive enough to contain a human-dwarfing ice cave, was gone by 1998. Grinnell Glacier, beloved by tourists and scientists alike, has lost 90% of its volume since 1850.
The dwindling glaciers amid the deeply chiseled landscape of this national park offer the clearest and most visible sign of climate change in America. It is an omen even a child can grasp in an instant: Ice that has lasted in these high alpine valleys since the end of the Stone Age will soon vanish.
"It's not just going to happen in my lifetime," said Dan Fagre, a 49-year-old ecologist who leads the U.S. Geological Survey team working to chronicle climate change in this park known as the Crown of the Continent. "It's going to happen during my career."
The unexpected speed of the demise of the glaciers has left scientists racing against time. They have only decades left -- nothing at all in geological time -- to understand these ancient frozen beasts before they disappear. "The scariest thing to me is realizing how fast these things are happening," said Blase Reardon, 39, an avalanche expert who has worked in the park for the last two years. "Being here is like having a front row seat at the Indianapolis 500."
The melting here is being mimicked around the world, from the snows of Mt. Kilimanjaro in Tanzania to the ice fields beneath Mt. Everest in the Himalayas. Experts predict that glaciers in the high Andes, the Swiss Alps and even Iceland could disappear in coming decades as well.
In contrast to these more remote, high-altitude areas, the accessibility of Glacier National Park gives scientists a chance to get the most intimate view possible of a dying glacier.
Since 1991, a team of scientists has measured the most ephemeral details of the glaciers. They have analyzed the cycles of precipitation and temperature that merge into the cold calculus of every glacier. They have dragged ground-penetrating radar over crevasses and risked skiing into avalanches to measure snowfall. They have analyzed soil carbon and counted frog eggs to document the unique ecology of glaciers and their meltwater streams.
But for all the gigabytes of data the team has accumulated, they realize they have only scratched the surface. The transformation of the park has turned out to be far more complex than anyone imagined. For example, even as most glaciers here race toward extinction, a handful seem to effortlessly maintain their grip on mountain peaks.
"It makes you question what you know," said Fagre, "which is the real point of science."
While the team has spent much of its tenure here talking about stream flow data, snowfall records and vegetation dynamics, they have started talking about something new: the loss of beauty. These scientists know they are recording the last vestiges of a world that may soon exist only in their computers, photographs and memories -- a world their grandchildren may never see.
"When the permanent parts of the landscape start disappearing, that's unsettling," said Fagre, who has lived and worked in the park for more than a decade. "It's still a beautiful mountain, but without glaciers, an identity is lost."
To glaciologists who thrill to see the groaning dynamics of ice in real time, there still is beauty in the rocky new landscapes. Glaciers often drip away into milky lakes of "unusual, gorgeous, turquoise, practically indescribable color," said Jeffrey Kargel, a USGS scientist who monitors many of the world's wasting glaciers from space. The color is a product of light reflecting off "glacial flour," or ground-up rock that floats in meltwater.
The terrain left behind by a retreating glacier is like land recovering from fire, Kargel said. It may look devastated, scarred and littered with boulders. But soon, lichens, grasses and wildflowers grow. Those who stand at the edge of retreating glaciers are likely standing where no human has stood before. "It's not all doom and gloom," Kargel said.
Most casual visitors to these mountains have little idea that most glaciers in the Lower 48 are on the way out. The handful of "itty-bitty" glaciers in the Sierra Nevada "are glaciers only by the most technical sense of the term," Kargel said. Most glaciers that remain there are rock glaciers -- flowing fields of rock interspersed with ice that don't look glacial at all. Alaska's glaciers are in dramatic retreat as well.
Some of this epochal change can be hard to detect, particularly for those who have spent much of their lives in the park.
The son of a seasonal ranger, Steve Frye spent his boyhood summers exploring the park's forests and peaks. In 1970, on his first park job, he sat in the Swiftcurrent lookout tower watching for fires out across the Continental Divide. His view included several glaciers, including Grinnell, the park's most famous.
At 54, Frye is the park's chief ranger and one of 16 Type I incident commanders charged with fighting the country's most complex forest fires. This summer, in between stints at devastating fires near Denver and in Oregon, Frye found time to make a nostalgic trip back to the lookout he staffed 32 years ago.
The changes in Grinnell didn't stand out, especially because other aspects of the timeless landscape looked so much the same. But when he saw a series of before-and-after photos showing how much Grinnell had changed since 1850, his response was different. "I wasn't shocked," he recalled, "but I was overwhelmed."
The pictures will do that.
In most areas with vanishing glaciers, there are few historical records documenting how the ice has responded to the warming of the planet during the last century -- or even the last decade. Here, an archive of 12,000 photos offers an unparalleled window into the last century.
The creation of this park, the nation's 10th, neatly coincides with the rise of photography. Boxes of photos of the park date back to the 19th century.
They are of use to scientists only if they can be compared with modern photographs taken from the same locations. So Fagre's team has retaken many of the aging photographs. It is exacting work that requires scouring topographic maps and hiking the backcountry for days to reach the same viewpoints early park photographers used.
"You get a little closer, you get a little further. You try to line up the mountain ridges," said Karen Holzer, a 35-year-old USGS scientist who has hiked, skied and kayaked around these glaciers for five years to help shoot this new generation of glacier images. "We get excited when we find a big rock that was up there 30 or 60 years ago."
Of 17 glaciers that have been rephotographed, Holzer said, four small ones in the park's shadiest, north-facing recesses have not changed at all. Twelve have shrunk considerably. And one, Boulder, disappeared.
A set of photos of Grinnell glacier through time now hangs in the park's Apgar visitor center. The images startle visitors who think of climate change only as some distant, far-off threat, Frye said.
The vanishing glaciers were among the first topics to come up after Mick Holm took over as superintendent this summer. People "wanted to know what I was going to do about stopping the glaciers," he said.
Holm could offer no consolation. While dismissing suggestions that Glacier National Park will need a new name once the glaciers go, he admits the questions raise some disconcerting issues.
"I don't know if people have taken the time to really think of Glacier National Park without glaciers," the eastern Montana native said. "We've always expected them to be here."
Though the glaciers have existed through human history, they were not always here. Today's mountain glaciers are about 7,000 years old and grew to their largest extent during the Little Ice Age, a period from 1450 to 1890 when temperatures were a few degrees colder than temperatures in the 1900s.
Even at their largest, today's glaciers were dwarfed by the 5,000-foot high rivers of ice that filled the park's valleys about 20,000 years ago at the end of the last great Ice Age. In that Ice Age, the Earth was chilled by a combination of small changes in its orbit and cyclic changes in levels of atmospheric carbon dioxide that are still not fully understood.
Glaciers take decades to respond to warming. Scientists say the melting of the glaciers seen today is largely because of leftover warming from the end of the Little Ice Age and global warming, the recent heating of our planet by 1 degree. Most scientists agree the recent warming is mainly a product of industrial activity.
The loss of ice worldwide is a crisis on many levels. Glaciers are natural water towers, providing steady flows of late-summer water to the drier farms and valleys far below. These streams are the lifeblood of mountain ecosystems. When warming is rapid, gushing meltwater can quickly dam into large lakes and burst in flash floods. Collapsing glaciers can crush small hamlets. In September, dozens of people died when a Russian village in the Caucasus Mountains was buried in ice.
The park is safe from such disasters. The relatively small glaciers here have no human settlements beneath them. In this wildlife-rich ecosystem, the ice may not even be the most important change rippling through the park, only the most visible.
For example, the Piegan glacier is one of the few in the park that has not shrunk in recent decades. But a photo comparison shows the landscape around the glacier is radically different.
A high alpine meadow that once stood beneath the ice is now filled with sub-alpine fir trees, which have been able to migrate to higher elevations because of the slightly increased temperatures. Such vegetation changes, along with the drier landscape expected to accompany the warming, dramatically alter the potential frequency and severity of forest fires.
Fagre said recent climate change has begun to alter stream flow and temperature, vegetation dynamics and soil content. Those small and unglamorous details reveal patterns of change and adaptation that will eventually play out in lower elevations where humans live and could cause large scale changes in animal reproduction, forestry and agriculture.
For example, changes in soil chemistry and temperature already are leading to changes in plant cover. Scientists expect the park's cedar-hemlock forests will expand in the future and that the distribution of one grizzly bear favorite -- huckleberry patches -- could change as well. Dwarf trees that cling to life at the tree line are sending up tall, strong leaders for the first time.
Changes to stream flow and temperature could alter the reproduction of the damsel and caddis flies that provide food for the fat Montana trout so coveted by fly fishermen.
But even as the details reveal more about the ecosystem, they frustrate Fagre's ability to understand the glaciers.
For the first years of the study, the phenomena seemed a simple matter of rising temperatures melting the ice. But closer analysis of temperature data from nearby Kalispell didn't fit that picture. Annual temperatures there have not warmed significantly in the last century -- the time when glaciers have retreated most.
Fagre's team recently started looking at the other half of the glacial equation -- precipitation. They paid close attention to a decades-long cycle called the Pacific Decadal Oscillation, an El Niño-like Pacific Ocean pattern that can dramatically alter snowfall patterns in the Pacific Northwest and the northern Rocky Mountains.
Analysis showed that for much of the last century, the pattern has been locked in a phase where there has been significantly less snow. The lack of snow helped explain, in part, why the glaciers retreated.
But the glaciers retreated even during periods with heavier precipitation, said Fagre, indicating that warmer global temperatures are likely to play a role in the loss of ice as well. The link between ice loss and global warming caused by humans is not as strong as in glaciers elsewhere, he said, but it still exists.
"We're doing the same thing. We're just not in lock step with the global trends," Fagre said. "That sloppiness is to be expected in a complex system like our planet."
It is a world of unexplained contradiction and complexity that keeps Fagre going.
He has routinely worked 60 hours a week since the project began and has no plans to slow down -- the glaciers are disappearing too fast to let him.
As long as they last, he will keep teasing secrets from them, measuring their size and monitoring the lakes of milky aquamarine meltwater pooling beneath them. He will monitor the firs, track bull trout populations and use powerful computers to model new forest fire cycles.
There is some comfort in the long columns of data he can generate, some satisfaction in knowing the careful work could one day help reduce ecological damage from retreating glaciers around the world.
But as he hikes through the mountains, Fagre, the son of a theologian, cannot shake his sense of loss.
"I'm an ecologist who knows climate change is neither good nor bad," he said as he hiked across a ridge overlooking a set of classic U-shaped glacial valleys amid 10,000 foot peaks.
"But I'm also a person who likes glaciers the way they are."