WIND RIVER RANGE, Wyo. — Here at the roof of the Continental Divide, one of the Rocky Mountains' largest glaciers is in retreat.
A new world is emerging in the wake of the receding ice. In a vast, glacially carved basin, where towering spires of granite dominate the skyline, a small colony of stunted Engelmann spruce has taken up residence in a pile of rocky debris, some 500 feet above the tree line. Bees flit among the yellow mountain asters dotting the boulder field at the glacier's base. Grass grows along a stream where there was, until recently, only snow and ice.
"It's a different place today," Darran Wells, an outdoor education professor at Central Wyoming College, observed from a research camp near the base of the Dinwoody Glacier on a recent evening. A regular visitor to the glacier over the last two decades, Wells offered a succinct take on its evolution over his nightly meal, a dehydrated serving of shepard's potato stew with beef.
"Every year, more grass, less snow," he said.
The largest concentration of glaciers in the American Rocky Mountains are melting, unseen, in this remote corner of Wyoming. More than 100 glaciers cover about 10,000 acres in the Wind River Range, according to a recent study by researchers at Portland State University. No American mountain range outside Alaska and Washington is covered in more ice.
The Wind River glaciers remain some of the least understood ice sheets in North America. Researchers don't have a firm grasp on the amount of water locked away in the alpine ice, and estimates of how much they contribute to local streams vary widely.
Answering those questions requires penetrating a rugged wilderness nearly the size of Rhode Island and climbing to elevations between 11,000 feet and 13,800 feet, where the glaciers hug the crest of the Continental Divide.
Today, a growing number of scientists are pushing into the backcountry to understand these icy reservoirs. Their concern: The Wind River glaciers are retreating just when Wyoming needs them most.
"If you haven't had proximity to these glaciers, if you haven't thought about where water comes from, it would be easy to understate or underestimate the implications of glacial ice loss in a state that has predominantly a semi-desert climate and certainly by contemporary climate models is going to be pretty significantly impacted by climate change," said Jacki Klancher, a professor of environmental science at Central Wyoming College.
The Wind River Range cuts a 120-mile path across western Wyoming, rising from the wavelike sand dunes of the Red Desert in the south and terminating amid the rolling forests that ring the entrances to Yellowstone and Grand Teton national parks in the north.
The range encompasses two national forests, three federal wilderness areas and the Wind River Indian Reservation. The mountains are popular among backpackers and climbers, but the lack of roads and the remoteness of this area mean the number of people pale in comparison with the crowds that pack Yellowstone and Grand Teton each summer.
Roughly three-quarters of the glaciers here hug the range's eastern slope. That is where the Dinwoody sits, occupying a stark basin capped by the 13,800-foot summit of Gannett Peak, Wyoming's tallest mountain.
When Wells first arrived here as a student on a National Outdoor Leadership School course in the late 1990s, the Dinwoody was blanketed in snow. Today, patches of bare ice blot its surface, revealing great twisting crevasses in its face. Each year, the ice climbs a little farther up the mountainside, said Wells, who at 46 maintains the trim physique of an adventure athlete.
The retreat hints at the wider challenges Wyoming faces as the climate warms. But, he said, "I think at this stage there is still a lot of denial, right. People don't want to admit it's a possibility because it's not a pretty picture."
In 1950, when researchers first measured the Dinwoody, they calculated its area at 850 acres. A follow-up study 50 years later concluded it was 540 acres.
The decline mirrors many glaciers in the range. One study in 2011 using aerial photographs concluded that many of the glaciers in Wind River lost on average 38 percent of their surface area over the latter half of the 20th century.
Glaciologists predict Glacier National Park will lose its ice sheets by 2080. The glaciers of the Cascades, the largest in the contiguous United States, are expected to hang on until roughly 2100. But there are few predictions for the future of the Dinwoody and its close neighbors.
Relatively few teams have tested the depth of the ice or examined other factors that could contribute to its demise. Both are essential to developing a prediction for how long the Dinwoody will last. It is this question Central Wyoming College researchers hope to answer.
In late August, Klancher and Wells led a team of roughly 15 undergraduates and researchers from Central Wyoming College, the University of Wyoming and the University of Redlands on their fourth summer expedition to the Dinwoody.
The trip, officially the Interdisciplinary Climate Change Expedition, is made possible by a five-year research permit from the U.S. Forest Service, which oversees this wilderness.
The wilderness designation means the glacier is inaccessible by helicopter or car. To reach it, the team loaded nine mules with 900 pounds of food, camping supplies, one ground-penetrating radar (the Noggin 100 MHz) — along with its batteries, cables, antenna and monitor — an incubator for snow samples, solar-powered batteries, test tubes, flow meters and other scientific instruments.
The 20-mile trip took more than two days, leading mules, professors and students 3,000 feet up and over a high alpine plateau and down several thousand feet into a valley, where they slowly weaved their way along a river in the direction of a boulder field until they finally reached the glacier's base. From there, backpacks replaced mules, and equipment was hauled the last 2 miles over the rocks to a high-altitude research camp at roughly 11,000 feet.