Mount Rainier’s glaciers are disappearing. What happens when they’re gone?

TACOMA – Paul Kennard knew Mount Rainier was in trouble when its most-visited tourist attraction melted.

“I think the real warning bell for a lot of people was – ‘have you heard of the Paradise ice caves?’ ” said Kennard, a retired National Park Service geomorphologist previously stationed at Mount Rainier National Park.

Once an 8-mile network of caves with an entrance in the lower part of Paradise Glacier, it was the most-visited tourist spot for decades before glacial melting caused large chunks of ice to begin to fall from the ceiling, endangering visitors and pushing officials to close access, he said.

Now, the caves are gone.

Kennard said the iconic caves were a sight to behold, with formations that shone a brilliant blue when he visited as a scientist in the early 1980s. The park closed public access to the historic caves – which had been drawing crowds since the 1920s – around 1980 due to the safety hazard, according to the National Park Service website.

The disappearing caves foreshadowed the lasting glacier loss that the mountain faces today, which is rapidly changing its landscape.

Scientists see a future where the mountain’s well-known ice sheets will soon be scarce at its lower elevations, redefining its ecosystem. Experts think Mount Rainier may lose its next glacier in the next five to 10 years.

As an active stratovolcano, the highest peak in the Cascade Range and the most glaciated mountain in the contiguous United States, Mount Rainier routinely gets around two million visitors a year.

At the start of the 20th century, Mount Rainier boasted 30 glaciers – currently, the National Park Service says there are 28. Recent surveys by other scientists have concluded there may now only be 26, and they estimate three more glaciers could be lost in the next twenty years.

After losing just one glacier in the 20th century, Mount Rainier may lose six in just the first half of the 21st century.

What makes a glacier? Which glaciers are at risk?

In the 20th century, the mountain lost the Paradise ice caves and the Williwakas Glacier. A 2023 National Park Service report surveying Mount Rainier’s glacial volume from 1896 to 2021 said those losses were “a harbinger of things to come.” The same study declared Stevens Glacier had disappeared.

A 2023 survey later carried out by Mauri Pelto, a glaciologist and director of the North Cascade Glacier Climate Project, declared the Pyramid and Van Trump glaciers inactive. The NPS report had previously described both glaciers as “critically endangered.”

Kennard, who retired in 2020 after two decades as an NPS regional geomorphologist, told the News Tribune a glacier is usually considered a moving body of ice – as snow and ice accumulate toward the top of the glacier, they begin to move downward, compacting the ice and forming crevasses. Kennard said as a glacier melts and loses volume, that movement stops, at which point it’s typically no longer considered a glacier.

Pelto, who is also a professor of environmental science at Nichols College, concluded that Pyramid and Van Trump had become too fragmented and still to be considered glaciers. Stevens Glacier – to the southeast – was officially removed from Mount Rainier National Park’s glacier inventory in 2023 because it lacked indications of movement.

Pelto, who has spent four decades studying glaciers, said glaciers are losing mass across the state and the world. Smaller ones are especially at risk, simply because they have less ice to lose, Pelto said. Those at lower elevations are also typically melting faster as they struggle under increasing temperatures, he said.

“There’s certain glaciers that don’t extend up toward the summit, and are less than maybe one square kilometer in area, and those are the glaciers that are going to be lost in the next 20 years,” Pelto said. “And so it’s really just a question of ‘when,’ not ‘if’ those glaciers are going to be lost.”

Claire Todd, professor and department chair of geological sciences at California State University, San Bernardino, said glaciers that begin at the top of the mountain and have a thick rocky debris cover – a layer of rock to insulate the ice from the sun’s rays – are less likely to disappear anytime soon.

Todd, whose research focuses on Emmons Glacier, which has the largest surface area of any glacier on Mount Rainier, said a horseshoe shape at the terminus, or bottom, of a glacier is a telltale sign of glacier melt. She said the horseshoe shape – in which the center of the glacier’s lower edge appears to be retreating faster and higher than its flanks – indicates ice flow from above is not replenishing the bottom of the glacier.

Glaciers that are at lower elevations and do not receive their ice supply from the summit are more likely to disappear, and sooner, Todd said.

Pelto said the southeastern Paradise Glacier and eastern Fryingpan and Ohanapecosh glaciers – all of which are at lower elevations on Mount Rainier – appear to be at high risk of being lost in the next 20 years. The Ohanapecosh Glacier has begun to fragment and will likely be the next glacier to go, he said. He thinks it has about five to 10 years left.

“The biggest fragment is still point one square kilometer, but it’s on that same trajectory,” Pelto said of the Ohanapecosh Glacier. “It looks like Van Trump did in 2012.”

How is a glacier loss being tracked?

Retired NPS geologist Jon Riedel said scientists have sought to track the difference between winter accumulation and summer melt at select glaciers on Mount Rainier. Riedel, who retired in 2021 after three decades with North Cascades National Park, said he started a glacier monitoring program with the park in 1993, which expanded to Mount Rainier in 2003.

The program selected the Nisqually and Emmons glaciers – which respectively lie on the southern and northeastern faces of the mountain – as index glaciers to monitor intensively and conduct fieldwork, but would also look at photo and satellite measurements of all the glaciers about every 10 years, Riedel said.

Although the glaciers have been receding over the past century, he added, some may have stabilized or even grown in size for some periods during that time. Yet, in the past two decades of the NPS glacier monitoring program’s presence at Mount Rainier, the glaciers have only thinned and receded, Riedel said. He added that during his last trip to Emmons Glacier with the NPS in September 2019, there were signs of huge stagnation at the lower level, meaning the glacier’s ice was barely moving, which he said was due to a lack of ice forming at its upper level – the accumulation zone.

“We have a lot of variability in our weather and so trends are difficult to tease out in short periods of time. Having said that, the trends were clear at Mount Rainier: that the glaciers were losing more to melt in the summer than they were gaining in the winter,” he said.

A Google Earth Engine timelapse shows the ice Mount Rainier has lost from 1984 to 2022.

Glaciologists have noticed the speed of glacier melt has been faster in recent years, which is another measurement scientists track during glacier monitoring surveys, Pelto added.

The large NPS study that measured glacier loss at Mount Rainier from 1896 to 2021 found glacial area had been reduced by 41.6% during that time.

Between 2015 and 2021, the study found the rate at which Mount Rainier glaciers were losing area was more than two times faster than the rate estimated for the period of 2009 to 2015.

The News Tribune contacted multiple scientists affiliated with the National Park Service over the course of several weeks; all eventually declined an interview and directed the News Tribune to a park spokesperson. Some said they were concerned about doing an interview due to the political climate. The National Park Service has experienced layoffs under the Trump administration and its plans to reduce federal spending, and is facing large proposed budget cuts – including the elimination of grants used for research about climate change, according to the New York Times.

Mount Rainier National Park spokesperson Terry Wildy told the News Tribune that Mount Rainier National Park was unable to provide an interview.

Wildy responded to the News Tribune’s inquiries to scientists with general information in an email. In the email, Wildy said Mount Rainier is an ideal location to study climate change because of its large range of elevation and glaciers that respond to changes in temperature and precipitation with measurable results.

“A range of forecasts of climate change in the next century may lead to significant changes in the glacier cover at Mount Rainier,” she said in the email. “These models indicate that lower-elevation glaciers may disappear completely in the next century, while those glaciers that start at the summit will persist, though, with terminus positions that are higher up on the mountain.”

She added that many ongoing studies track climate change on Mount Rainier, including weather stations, steam gauges and regular measurements of the 28 named glaciers. Park scientists also monitor various species of wildlife on the mountain, including wildflowers and low-elevation forests, Wildy said in the email, adding that this research is sometimes conducted in partnership with other government agencies or local universities.

All 28 of Mount Rainier’s glaciers have decreased in length, volume and thickness in the past century, although the overall trend of melting has been uneven and mixed with some periods of growth, Wildy said in the email. She added that glaciers on the south side of the mountain have melted more than those to the north, where the shadow of the mountain shelters them from the sun.

“Glaciers that start at relatively low elevations, like the Pyramid or Van Trump glaciers, have melted more than those that reach near the summit of the mountain, like the Nisqually or Emmons Glacier,” Wildy said in the email. “Some, like the Williwakas and Stevens glaciers on the south side have melted out completely, and others like the Pyramid and Van Trump glaciers are at risk for disappearing in the next decade.”

What does this mean for wildlife on and around Mount Rainier?

Jill Pelto, an artist and scientist who serves as the art director for the North Cascades Glacier Climate Project, said the glaciers have experienced drastic change, particularly in the past 10 years. Many glaciers’ retreat has been severe, an issue she hopes to capture and spread awareness of through her art, which combines data with landscapes to depict climate change, and often features glaciers.

In the past decade stretching back to 2015, climate change has increasingly caused intense heat waves and droughts that have accelerated glacier melt, she added. She has been conducting research with the project for 16 years and is the daughter of Mauri Pelto.

“I think maybe people don’t realize that all of these rivers, there’s a really huge percentage of them that’s fed by either glaciers or snowpack in the mountains, and we need these rivers for the hydropower that so much of the state is fueled by,” Jill Pelto said. “We need them for all of our agriculture, for the salmon … these rivers are going to be really impacted by glaciers diminishing, and water resources in the Pacific Northwest might seem infinite, but they’re not.”

According to the NPS, Mount Rainier’s glaciers feed into the White, Carbon, Puyallup, Nisqually, Ohanapecosh and Cowlitz rivers, which provide a large source of freshwater for the area, for human use and wildlife habitats – including federally threatened bull trout, Puget Sound steelhead trout and chinook salmon species, according to the NPS website.

The Ohanapecosh, White and Nisqually rivers are fed by the Ohanapecosh, Emmons and Nisqually glaciers, respectively, along with some other contributing glaciers. The Ohanapecosh River, which serves as the main head of the Cowlitz River, also flows through the popular Ohanapecosh and La Wis Wis Campgrounds at Mount Rainier.

Jacques White, chief executive officer of Long Live the Kings (LLTK), a nonprofit organization focused on restoring wild salmon and steelhead in the Pacific Northwest, told the News Tribune climate change has caused flow problems in rivers in the Puget Sound area.

Water temperatures are consistently higher than they were 20, 30 or 40 years ago, which can affect the ability of adult fish to swim toward spawning points, he said. Glacier-fed rivers such as the Nisqually and Puyallup are experiencing reduced flows, which can likely be attributed to less snowpack and to snow melting earlier in the year than in years before, White said.

LLTK also works with the Puyallup and Nisqually tribes’ natural resources staffs to monitor water quality and fish habitats in the Puyallup and Nisqually rivers, White said, adding that both rivers are important to each tribe’s cultural heritage and way of life. White said glacier melt has begun to threaten these habitats – without the same amount of cold glacier water to provide the right temperatures for them, coho salmon, spring chinook salmon and steelhead trout cannot stay to rear in the rivers for as long as before.

“If fish or wildlife depend on large volumes of cold water into summer, they’re not getting it because the major melt has occurred earlier, and then through the summer, you’re just now starting to melt the glaciers,” White said. “The glaciers are, of course, smaller than they were, so the volume of water coming out of the river during peak temperature periods and the annual cycle is less.”

Rivers fed by larger glaciers will also likely feel effects. Todd said Emmons Glacier, which feeds the White River, can expect to see earlier spring melt in the future, which would change the timing of glacier water delivery to the river. Future extreme heat events may also cause releases of a lot of water in a short period of time, making the river’s water levels less predictable, she said.

Salmon are an integral part of the local ecosystem and the transfer of nitrogen, an essential nutrient, White added.

He said the salmon are an important source of food for other species at various stages of their development: birds and other river fish eat their eggs in rivers; seals, fish and birds eat them in the Puget Sound; and farther out to sea, they are eaten by salmon sharks and orcas. White added that upon their return to the rivers to spawn, the salmon again provide a food source for animals such as bears or eagles, or die on the riverbank and feed plants and insects.

The loss of salmon populations could cause a variety of environmental issues and threaten other animal species, White said. The Southern Resident killer whales, for example, depend almost entirely on salmon for their survival.

“Salmon are essentially a nutrient conveyor belt that brings nutrients from the ocean and fertilizes our coastal watersheds, which otherwise would probably be pretty nutrient poor,” White said. “So salmon are an amazing kind of biological transfer mechanism to get nutrients from one place to another, and in large quantities. When you have millions of pink salmon returning, for example, to a river, that’s a lot of biomass that’s coming back.”

Decreased freshwater flow from the glaciers into the rivers can also disrupt estuary habitats, making it more difficult for fish to acclimate to salt water as they try to go out to sea, he said, adding that young chinook salmon often spend a prolonged period of time growing and developing in these shallow water environments, which could pose another threat to their population.

The mountain has also seen changes in its plant life, said Janneke Hille Ris Lambers, a professor of plant ecology at ETH Zurich and an affiliate professor in the University of Washington Department of Biology. Mount Rainier is known for its wildflower blooms, which she has studied with UW.

Her research suggests that peak wildflower blooms on Mount Rainier will likely occur earlier in the year if climate change continues to bring warmer average temperatures, she said – in 2015, for example, especially warm and dry weather caused an early snowmelt that corresponded to an early bloom.

She added that Mount Rainier’s sharp elevation changes and corresponding climate variation can help scientists predict how plant performance might change as the climate gets warmer or colder in the future.

“You can make those predictions also based on the elevational gradient,” she said. “So, for example, at Mount Rainier, if we stand at Paradise and look around us, we might predict that the way Paradise will look in 50 to 100 years – a proxy for that is basically walking downhill the same amount of climate, same amount of temperature, as we expect to change there.”

Hille Ris Lambers said the wildflowers’ blooms have also spread out over time as average temperatures have increased and snow has melted earlier.

She said because of the limited bloom season on the mountain, many plant species rush to flower at the same time before snow returns in the fall; now, as snow melts earlier, some species will adjust to bloom earlier than others, diminishing overlap of the different species’ blooms.

“For visitors, one of the things that I think we can say is that, like, these beautiful wildflower blooms that people come to visit, that will happen earlier. It may not be as spectacular in terms of the diversity of colors,” Hille Ris Lambers said. “… If you have kids, like, right now, a lot of that action is happening during summer vacation, which is really convenient … if that happens before school ends, that might be a little more challenging.”

It is unclear what impacts a longer flowering season would have on pollinator species, she said, adding that questions remain of whether a longer period of bloom could be beneficial or whether impacts on pollen or on the availability of certain plants throughout the summer could be detrimental.

Certain alpine plant species that are better adapted to the cold may struggle to compete with plant species that fare better in warmer climates, she said.

“As temperatures continue to warm, the expectation is that species from lower elevations that maybe can’t tolerate those harsh climates but are faster growers will colonize upward and displace those sort of iconic, alpine wildflowers,” Hille Ris Lambers said. “I will say that one big mystery is the rate at which that will happen, because that also requires those species to get there, right, and sometimes they have seeds that don’t go very far.”

What does glacier loss mean for people?

Climate change leading to a global increase in average temperatures is a long-term process that has been overwhelmingly confirmed by scientific evidence and consensus, Wildy, the park spokesperson, said in her email. As glaciers are affected by this process, the diminished snowpack threatens water supplies, irrigation and hydroelectric power in the area, Wildy said.

Scientists’ fieldwork routes have had to change as the landscape on Mount Rainier has changed and sometimes become more hazardous, Riedel said. Glaciers help hold the mountain’s rocks in place, Mauri Pelto said, adding that when that snow and ice melts in the summer, the ground becomes unstable, leading to rockfalls that can make it more difficult for scientists to conduct fieldwork.

In his work monitoring glaciers in the North Cascades, this problem has changed the routes they take and has sometimes made it too risky to reach certain places for data collection, he said.

Rockfalls can also spell danger for recreational climbers or hikers – in 2019, one climber was killed and two others were injured in a rockfall that struck a campsite at Liberty Ridge on the northwest part of Mount Rainier.

Wildy also said in the email that glacier loss increases the frequency of glacial outburst floods and debris flows.

Kennard described these flows as highly destructive landslides – such events damage park infrastructure and have already closed the Carbon River Road to vehicles due to repeated flooding.

Much of Westside Road also remains an active geohazard zone that is also closed to vehicles due to rock fall danger.

Are we approaching a future in which Mount Rainier will have no snow?

Mount Rainier’s especially high elevation – 14,410 feet, the highest peak in the Cascade Range – keeps its summit colder than that of shorter mountains, which helps preserve its higher glaciers’ supply of ice, Riedel said. Kennard said it is unlikely Mount Rainier will be completely bare anytime soon, but that if the trend does not change, the only glaciers left will be at the mountain’s higher elevations.

The mountain will likely melt unevenly, because the northern side’s snow is shielded from the sun more than the southern face, Kennard added. The southern face of the mountain will likely see glacier loss at higher elevations than the northern side.

“On the north side, you’ll see the changes will be slower and more muted and kind of gradual,” Kennard said. “So I expect you’ll see worse – it’ll be more pronounced on the south side and less on the north.”

Mauri Pelto said that as the glaciers continue to lose ice, the mountain will look different from afar, especially in the late summer. Its icy shine will likely appear more brown or gray outside of the winter months, he said.

Glaciers that are south-facing, perched at a medium elevation and that lack an accumulation area connected to the highest elevations of the mountain are the most vulnerable, Todd added. The Ohanapecosh, Fryingpan and Paradise glaciers all fit this description.

Riedel also said any glacier that does not head at the top of the mountain will likely face the largest risk of disappearing in the next couple decades, and that many large glaciers will likely see losses of their lower levels in the near future.

“That’s a huge amount of ice, lower Emmons Glacier, that is, in fact, you know, stagnating, and when that’s gone, that’s going to be a big change in the size of Emmons Glacier,” he said. “It won’t be gradual, all of a sudden, it’ll be ‘Boom!’ – this upper glacier is now cut off, and there’s this stagnant, isolated ice mass in the lower valley. And that could happen with Nisqually, I suppose, too.”