Tram Interpretive Experience

As important as tectonic activity was, and still is, to the formation of the Tetons, so is glaciation. While the Teton Fault has been uplifting the peaks for around 10 million years, glaciers sculpted the range’s distinctive U-shaped canyons, cirques, and hanging valleys, carving out the depressions that are now lakes. Granite Canyon, in Grand Teton National Park and immediately to the north of JHMR, is a glacier-carved U-shaped valley. If you’re a skier or a hiker who likes JHMR’s Cirque area, you can thank glaciers.

The two most recent glaciations to have been at work in Jackson Hole are the Pinedale, from 50,000 to 14,000 years ago, and the Bull Lake, which occurred about 200,000 years ago and buried the entire valley under about 2,000 feet of ice. While the Bull Lake glaciation deposited the gravel and cobbles that are the base of today’s expansive sagebrush-covered valley floor, it was the Pinedale glaciation that sculpted the Tetons.

Rivers and glaciers both create canyons. Canyons with glacial origins have a U-shape (in contrast with river-carved valleys, which are V-shaped). During the Pinedale glaciation, glaciers formed in the Tetons and flowed downhill, eroding canyons and widening their floors and over-steepening their walls. In addition to Granite Canyon, examples of this include Cascade, Paintbrush, and Death Canyons, all of which are in Grand Teton National Park. Glaciers are also responsible for most of the lakes in the Tetons, including Jackson and Jenny Lakes, which were formed when meltwater filled holes left behind by retreating glaciers.

While glaciers are no longer shaping the Tetons, tectonic activity continues its work on the range. Due to the upthrust of the Teton Fault, the Tetons are still growing, albeit at the very slow rate of approximately 1 millimeter a year.

To hike through the work of glaciers, take the Cirque Trail from the top of the Bridger Gondola to the top of the Aerial Tram (or from the top of the tram down to the top of Bridger Gondola). This 1.8 mile trail crosses one of the many cirques carved in the Tetons by glaciers during the Pinedale glaciation period.

If you’re looking for something longer, consider taking the Aerial Tram to the top of JHMR and then hiking to Marion Lake and down Granite Canyon. A 6.25 mile hike from the top of the tram, Marion Lake is a depression left behind by a Pinedale-period glacier that filled with water. Enjoy lunch at the lake and then you can retrace your route back to the top of the tram or hike about 9 miles down the length of Granite Canyon and back to the JHMR base area. If you head down Granite Canyon, keep your eyes peeled for polished bedrock, another feature of glaciation.

Today there are 10 named glaciers and one unnamed glacier in the Tetons. All of these formed during the Little Ice Age (1350-1850AD) and have been mostly retreating since the late 1800s. (The exception is between the mid-1970s and mid-1980s, when the glaciers were stable.) The Tetons’ glaciers were first surveyed in the late 1920s and have been surveyed periodically since. The Teton, Middle Teton, Schoolroom, Petersen, and Falling Ice Glaciers are surveyed annually. While JHMR has some year-round snowfields, none of the Tetons’ 11 glaciers are at JHMR.

There is no hole in Jackson Hole. “Hole” was a term 19th century trappers and explorers used to describe large, low-lying valleys. The valley itself—ringed by mountains—is the hole. These same trappers called Teton Valley, on the west side of the Tetons, Pierre’s Hole, although that name didn’t stick like Jackson Hole did.

Although wolverines look like small, squatty bears, they are members of the weasel family. (Weighing between 30 and 50 pounds, they’re the largest land-dwelling member of the weasel family. We put the “land-dwelling” qualifier in there because otters are also members of the weasel family. Giant otters have a longer body length than wolverines and sea otters can weigh more). Evolutionary traits that allow wolverines to live in habitat like that found at the top of the Aerial Tram include paws that act as snowshoes and that also have built in crampons; the tip of each of a wolverine’s 20 toes is curved and sharp enough to allow it to scale a frozen waterfall or cliff without difficulty.

We don’t know as much about wolverines as we’d like, though. The species is notoriously difficult to study in the wild because it is highly sensitive to human disturbances and also because wolverines are amazing long distance travelers, roaming and hunting over territories as large as 600 square miles. Also, there just aren’t that many—only between 250 and 300 in the lower 48 states. In the Tetons it is estimated that there are fewer than 10 wolverines.

In 2023, the U.S. Fish and Wildlife Service listed the North American wolverine in the contiguous U.S. as a threatened species under the Endangered Species Act, citing current and increasing impacts of climate change and associated habitat degradation and fragmentation as contributing to the species’ decline.

Photo taken by Vladimir Cech

Resilient Residents

Black Rosy Finches are the only bird that lives year-round in the highest reaches of JHMR, but more than 350 species of birds have been observed on the Bridger-Teton National Forest, on which JHMR sits. Just because a bird has been observed on the BTNF, which is 3.4 million acres (bigger than Grand Teton and Yellowstone National Parks combined and the third largest national forest outside of Alaska), doesn’t mean that it has a presence at JHMR, but, it’s safe to write that it’s possible to observe a couple of hundred species of birds at the resort. Meet a handful of species likely to be spotted around the top of the tram in the summer.

As industrious as they are resourceful, rock wrens might have one of the shortest migrations of any of JHMR’s migratory birds (if not the shortest): between the bottom and top of the resort. The species, which is not a great flier (perhaps explaining its short migration route), builds nests and spends the summer in cavities and holes in rocks at high altitude. When winters come, they fly downslope. Unlike some animal species that are sensitive to humans and human disturbance, like bighorn sheep and wolverines, rock wrens do well in altered landscapes. Rock wren nests have been found in restored Mayan and Aztec ruins, road cuts, gravel pits, and even refuse heaps. At the top of the Aerial Tram there are plenty of rocks in which they can build their nests, though. While rock wren nests themselves are often hidden, the birds often build a noticeable “walkway” that leads to the nest cavity. These walkways can be elaborate, using flat stones and small sticks and even human-made objects.

Paul Marvin, XC576854. Accessible at www.xeno-canto.org/576854.

Growing at the Edge of Life

“Lichens are so important at high elevations in and around Jackson Hole,” says Trevor Bloom, Forest Botanist with the Bridger-Teton National Forest, in which JHMR is located. As important as lichens are to our high altitude habitats, they are even more fragile. “At the top of the tram, lichen can take hundreds of years to accumulate, and be disturbed with just one step off the trail,” Bloom says.

Lichen, which isn’t a single organism, but a symbiotic partnership of a fungus and algae or cyanobacteria, is integral to life in the high alpine because it both creates soil and also helps maintain soil structure. Lichen species that grow over rocks weather minerals from them, which, very (very) slowly breaks the rocks down into soil. And then there are lichen species that form biocrusts on soil and help with soil cohesion, preventing water and wind erosion. “A lot of the alpine plants we know would not be able to survive without lichen,” Bloom says.

Lichens, some of which are considered to be the oldest living organisms on the planet, are also a food source for high alpine animals including bighorn sheep and pikas. “Lichen isn’t necessarily a significant food source, but in a time of need like winter, when exposed vegetation is scarce, lichen might be all there is, which makes it very valuable,” says Ashley Egan, a BTNF biologist.

Lichens’ role in high elevation habitat makes it that much more important to stay on trails when hiking around the top of the tram and other Teton peaks. “For sure you’ll risk trampling lichen biocrusts in addition to alpine plants, some of which can take 100 years to establish, if you step off the trail,” Bloom says. JHMR is working with an independent botanist to see if some high alpine plants and lichen can be successfully moved but this work is not yet conclusive. “The best thing to do is stay on trails and not disturb them in the first place,” Bloom says.

Some lichen, like Wolf lichen, a bright yellow-green lichen that grows on trees at JHMR from the base area to the top of treeline, are poisonous. Wolf lichen got its common name because it was used in 17th and 18th century Europe to poison wolves. (It was also used to poison foxes and its scientific name, Letharia vulpina, relates to this; “vulpes” means “fox” in Latin.) Some Native American tribes used wolf lichen for poisoned arrowheads. While wolf lichen is poisonous to carnivores, it is not poisonous to the tree it grows on, nor to a handful of small mammals including rabbits, hedgehogs, and mice. And wolf lichen is more than a poison; Indigenous people in the interior of British Columbia used it as poultice for swelling and bruises and tea made from it was used to stop bleeding.

About 120 species of lichens have been identified in the Tetons through surveying at seven areas in the range, including Granite Canyon (just north of JHMR) and Rendezvous Mountain at the top of the tram. Just over half (64) of the identified species grow on rock. 25 species grow on soil; 25 species grow on wood and bark; six species are on moss on soil or rock. At the range’s lower elevations and in its forests the survey team found the lichens they expected—ones similar to those collected from Yellowstone National Park and Montana. The lichen communities found in the high alpine of the Tetons were significantly different from those surveyed at similar elevations on the Beartooth Plateau and in Yellowstone National Park, though. The survey team surmised that this difference had to do with the steep slopes of the Tetons, which cause relatively more unstable soil and rock substrates, making it harder for lichens to establish.

Stewardship for Survival

“I don’t know that a stand of whitebark exists at JHMR that has no beetles and has no white pine blister rust,” says Nancy Bockino, a whitebark field ecologist that has been studying the species in the Tetons, including those at JHMR, for more than 20 years. “There are whitebark that don’t have beetles and whitebark that don’t have blister rust, and those are the ones that we target to take care of.” This isn’t true only for the whitebark at JHMR, but throughout the Greater Yellowstone Ecosystem (GYE). It was because of the threat of MPB and blister rust that whitebark pine were listed as “threatened” under the Endangered Species Act in 2022; it is the widest-ranging tree species ever listed.

While mountain pine beetles (MPB) are native to the GYE, climate change has allowed their population to swell to epidemic proportions much more frequently, for longer durations, and also more widespread than in the past. Until the mid-20th century, there was a MPB epidemic about once every 60 years. There have been two epidemics in the GYE since 2004.

White pine blister rust is an invasive fungus native to Asia. It arrived in the U.S. in the early 1900s via a shipment of Western white pines from Europe and it quickly spread from the West Coast. But it wasn’t until the 1990s that blister rust’s potential impact on whitebark raised concerns. The fungus forms cankers that kill a tree’s living tissue. Stressed whitebarks have less energy to fight off MBP and whitebarks fighting off MPB have less energy to fight off white pine blister rust.

It’s not as hopeless as it sounds, though. About 25% of the whitebark in the overall population have a natural genetic resistance to white pine blister rust. Since this has been discovered, researchers across the expanse of whitebark pine habitat have sought to identify these “plus” and “elite” trees. Plus trees are WBP that, in the field, appear to have a genetic resistance to white pine blister rust; an elite tree is a plus tree whose genetic resistance has been tested and proven. USDA nurseries test if a plus tree is an elite tree by subjecting the seedlings of plus trees to spores of blister rust. Uninfected seedlings mean the parent tree is an elite tree. One elite tree has been proven from four identified plus trees at JHMR. 

Cones from elite WBP trees from across the region, including JHMR’s elite tree, are sent to a USDA nursery in Coeur d’Alene, Idaho where they are grown into seedlings and then sent out to be replanted. In the early 2010s, JHMR planted about 1,000 rust-resistant whitebark seedlings from the Coeur d’Alene nursery. Another 1,500 rust-resistant whitebark seedlings will be planted at the resort in 2025.

You can identify a whitebark infected with white pine blister rust because it will have what looks like macaroni-and-cheese powder on its trunk or branches. This “powder” are the reproductive cells of the fungus.

It’s not just the wildflowers on Cody Peak’s fossil-y dolomite and limestone that are worthy of attention. To date, 482 plants have been identified at JHMR. “JHMR is one of the best studied and surveyed areas of the Bridger-Teton National Forest at this point,” says Trevor Bloom, Forest Botanist at the Bridger-Teton National Forest. (JHMR sits on the BTNF.) Nine of these 482 species are forbs or flowers that are considered sensitive, either by the USDA Forest Service or by the state of Wyoming, which maintains a National Diversity Database. The three species considered rare and important to the USFS—largeflower triteleia (Triteleia grandiflora), Broadlipped Twayblade (Listera convallarioides), and Payson’s Bladderpod (Lesquerella paysonii)—require that JHMR, before doing any project, whether building a new hiking trail or installing a new ski lift, survey the project site for their presence. If any of these three species are found, JHMR must take mitigation efforts.

While Jackson Hole and the mountains surrounding it used to be part of an ocean, today the Snake River, easily seen from the top of the tram, is the valley’s main water. More than 1,000 miles long, the Snake is the largest tributary of the Columbia River, the continent’s largest river that flows into the Pacific Ocean. The Snake’s headwaters—where it starts—is just north of Jackson Hole, on Two Oceans Plateau in Yellowstone National Park. In 2009, the Craig Thomas Snake River Headwaters Legacy Act designated 414 miles of rivers and streams in the Snake River Headwaters region as “Wild and Scenic.”

The Snake River in Jackson Hole is special for many reasons, including its healthy population of the only species of trout native to Wyoming, cutthroat trout. Elsewhere, cutthroat trout populations are in decline. There were 14 unique subspecies of the trout that evolved in western North America. Thanks to human development and invasive species like brook, brown, and rainbow trout, two of these are now extinct and the rest are hurting. The Snake River watershed in Jackson Hole is the last, best, and largest watershed still dominated by cutthroat trout.

There are a couple of theories for why cutthroats in the Upper Snake have fared better than cutthroat in other major river systems in the West: 1. It is high elevation and fed by winter snowpacks that, to date, haven’t deviated that much from their historic norms even as the climate warms. 2. The number and scale of the federally protected lands in the region—there’s Grand Teton and Yellowstone National Parks and also the Bridger-Teton National Forest, which is bigger in size than Grand Teton and Yellowstone combined—keeps significant human development at bay.

The Greater Yellowstone Ecosystem is touted as being one of the few remaining intact ecosystems on the planet. People travel to the GYE to see all of the same terrestrial wildlife that lived here before the colonization of the area, including bison, wolves, moose, elk, and pronghorn antelope. Leslie Steen, the Jackson-based Wyoming State Director of Wyoming Trout Unlimited, told Jackson Hole magazine, “Not that many people know that under the water, we also have something that’s similarly precious and unique.”

Each year, mule deer travel up to 250 miles between the Tetons and Wyoming’s Red Desert—facing highways, rivers, fences, and more. This is the longest documented mule deer migration in the world, and just one of many epic journeys across the Greater Yellowstone Ecosystem (GYE), a 22-million-acre area spanning parts of three states and home to six migrating big game species.

Large-scale animal migrations have largely disappeared around the globe, with only a few remaining: caribou in the Arctic, wildebeests in Africa, and big game in the GYE. “There’s a tremendous opportunity to conserve migration here,” says Matt Kauffman, leader of the Wyoming Migration Initiative.

While migration tracking has a long history—Native tribes followed game for centuries, and early state biologists used snow tracks—modern GPS collars revolutionized the science. Researchers mapped the 150-mile Path of the Pronghorn and the Red Desert to Hoback mule deer route. Today, there are about 40 known migration paths in Wyoming, with efforts underway to protect them.

Key policy wins include:

• 2008: Path of the Pronghorn becomes the U.S.’s only federally designated wildlife corridor.
  
  

• 2018: Interior Dept. signs order supporting migration habitat.
  
  

• 2020: Wyoming enacts the nation’s first executive order to protect state-identified migration routes.
  
  

In 2016, researchers collared a mule deer—later named Deer 255—in the Red Desert. She went on to complete a 242-mile migration to the Tetons, the longest mule deer migration ever recorded. Most deer in her group migrate about 150 miles. Deer 255 died in April 2024, likely killed by a mountain lion.