You are here

Share
Mount Denali seen from the park road

The crown of Mount Denali, seen from the park road/ Kim O'Connell

Searching For Denali

The tallest mountain in North America is known for making its own weather. Now its weather patterns and temperatures are the subject of scientific scrutiny in a warming climate.  

By Kim O’Connell

“It’s got to be right there,” I said, glancing between the map on my phone and the swirl of clouds in the distance. “But it isn’t.”

My family and I were headed north on Alaska’s Parks Highway to spend part of our summer vacation in Denali National Park and Preserve. As we rounded every curve or crested every hill along the scenic route, we expected to see the peak that gives the park its name: Mount Denali, the tallest mountain in North America. If the weather was clear enough, we were told that we would be able to see the mountain all the way from Anchorage, about 240 miles away. That’s like being able to see the Statue of Liberty from the Washington Monument.

And yet, despite the blue sky and abundant sunshine on this late July day, Mount Denali was completely shrouded in clouds. This is common in summer, when visitors have only a 30 percent chance of spying the mountain because of persistent cloud cover, a source of frustration and delight for people who venture this far north to see what the Indigenous Athabaskan people called “the high one.” Even with lesser but still-stunning peaks of the Alaska Range all around us, and purple profusions of blooming fireweed along the road as we approached the national park, we couldn’t help but feel disappointed.

Denali is a land of “permanent winter.” Three quarters of the mountain are covered in snow and ice, with glaciers up to 45 miles long. At 20,310 feet of elevation, and 20,194 feet of topographic prominence, meaning its relative relief compared to its surroundings, Mount Denali rises so dramatically and is so isolated from nearby peaks that it creates its own distinct weather as moisture-laden air is pushed upwards as it slams into the Alaska Range. It could be sunny and mild elsewhere in the 6-million-acre national park while the mountain itself is frigid and wrapped with rain, snow, and clouds.

Yet the Denali of the past and present is most likely not the Denali of the future. Even in Alaska, Denali is not immune to the effects of climate change. Relying on high-altitude weather stations on Denali and research drawn from locations throughout the park, scientists have been tracking weather patterns and temperatures at the park for decades and have found a distinct warming trend. Seeing the mountain was proving elusive, but we would soon see one of the effects of climate change for ourselves.

No Longer Permanent

Dr. Vladimir Romanovsky is the head of the Geophysical Institute Permafrost Laboratory at the University of Alaska Fairbanks, where he has been studying permafrost changes at Denali and other parts of Alaska for years. When I reached him to talk about climate change and how it was affecting Denali, he wasn’t in his normal subarctic office at the university, but in Chicago, where he was presenting a paper on the topic at the annual meeting of the American Geophysical Union.

“We have almost continuous data going back 40 years and we use that data to analyze what changes in permafrost are happening because of changes in climate,” Romanovsky explained to me. “We use that data in models that are created to forecast what will happen to permafrost in the future—why permafrost is changing—and make some projections. Permafrost is just following climate, and if the climate is changing, permafrost is changing.”

Most of Denali National Park, like 85 percent of Alaska, is underlain with permafrost, a thick layer of continually frozen soil underground that is so reliably rock-solid that roads, buildings, and other infrastructure can be built on the surface above it. Acting like a gigantic freezer for storing biomass—ancient organic material from layers of decaying plant and animal matter—arctic permafrost contains an estimated 1,700 billion metric tons of carbon, according to NASA. As the planet warms and permafrost thaws, however, this carbon is released into the atmosphere, further contributing to global warming. Other problems quickly follow in the form of landslides, sinkholes, slumping ground, and disappearing lakes.

Permafrost changes in Denali, past and future

Comparing mean annual ground temperatures in Denali National Park can serve as a helpful tool to forecast future loss of permafrost. It may not be as clear as black and white, but in purple (colder) and red (warmer), Denali's wintry landscape might look vastly different within the next 80 years. Figures begin at 1951 and end at the year 2100/Compiled from a 2012 paper of the Geophysical Institute, University of Alaska Fairbanks

One recent National Park Service study published in the journal Arctic, Antarctic, and Alpine Research showed that the park’s permafrost cover has dropped from about 75 percent in the 1950s to around 50 percent now. From 2014 to 2019, Denali saw a mean temperature increase of nearly 3.6°F (2°C) over the previous 30 years, a higher increase than Alaska as a whole.

“The largest temperature increases have occurred during the cold season,” wrote the authors David K. Swanson, Pamela J. Sousanes, and Ken Hill, all NPS scientists. “[They] are attributed to both global and climatic warming and regional changes in atmospheric circulation. The Arctic and central Alaskan national parks are at the forefront of these changes.”

If the temperatures observed during 2014 to 2019 persist, the authors said, Denali and other similar Alaskan environments will see widespread degradation of permafrost, and climate models indicate that these warm conditions could be the norm within the next 30 years.

Pretty Rocks landslide

The Pretty Rocks landslide at Denali, which has closed the park road at milepost 43 at least through 2024. / NPS

Already, the park is wrestling with a major issue that is a direct result of thawing permafrost—the Pretty Rocks landslide, which occurred around mile 45 of the park’s 92-mile road, the only way in or out of the park’s interior by automobile. Park staff had been aware of shifting ground in that area for decades, but it had been moving so slowly that the park was always able to keep up and regrade or maintain the road to keep it safe and drivable.

But that began to change in the warmer year of 2014; according to NPS data published on its web site, the rate of road movement at Pretty Rocks evolved from “inches per year before 2014 to inches per month in 2017, inches per week in 2018, inches per day in 2019, and up to 0.65 inches per hour in 2021.” In late summer 2021, the park had no choice but to close the road entirely at the 43-mile point. And the NPS has announced that the park road will remain closed from that point on through at least 2024 while a bridge is built across the slide area.

“Denali’s park road is one of the most impacted pieces of infrastructure [due to the loss of permafrost],” Romanovsky says. Because Denali on average is right on the edge of the freeze-thaw temperature threshold, he adds, the park’s permafrost is uneven, and so it's hard to predict where the next failure might occur.

“Those rocks are old, lots of geologic history, with tectonic movement of crust and development of cracks and fractured zones,” explains Romanovsky. “Those rocks are not monolithic, there are some zones in those rocks that are much less solid, and water gets into these fractured zones and freezes…so with permafrost that is already pretty close to this thawing threshold, the ice melts and this makes these slopes much less stable, and now they can move and if part is frozen, it can easily slide downhill. And this is already happening.”

Finding Denali

My family and I had only two days to spend in Denali, and the road closure affected our decision to stick to the front country of the park. In a forward-thinking approach to protecting the park’s wild character, the Park Service requires that all visitors board a bus to travel the park road beyond mile 15. Views from the bus become increasingly spectacular the farther into the interior one goes; grizzly bear, moose, and elk sightings are common, and the mountain looms especially large towards the terminus at Wonder Lake. The only potential downside is that you spend many hours sitting. With less of the park accessible via bus, and having just made the four-hour-plus drive north from Anchorage, we wanted to spend more of our limited time hiking, so we opted to stay within the first 15 miles. 

The Savage River trail

The scenic Savage River area of Denali National Park. / Kim O'Connell

The park still afforded us spectacular views. We spotted two moose grazing in a field amid the taiga forest, and a sole elk walking along a rocky stream. Near the Savage River we hiked along the rushing waterway with our heads trained upwards, searching for Dall sheep on the surrounding high peaks. Temperatures were mild, in the low 60s Fahrenheit, but I knew that on the snow- and ice-covered summit of Mount Denali the temperature was far, far colder, likely well below 0 degrees. I could well imagine the mountaintop, but I couldn’t see it. Clouds still hung around the mountain like sheets on a clothesline.

In another study co-led by Romanovsky, NPS’s David Swanson, and others, the scientists determined that in the interior Alaskan parks, the loss of near-surface permafrost will be severe in the coming years. In Denali, the authors predict, the distribution of near-surface permafrost is expected to decrease from the current 51 percent to 6 percent and in Wrangell-St. Elias National Park from the current 51 percent to 30 percent by 2060.

Romanovsky’s staff is now engaged with the Park Service on an ongoing fieldwork project to gather even more data in Denali.

“When we’ve done modeling in the past, at that time we didn’t have any field work,” he explains. “We just collected existing data and applied our model to the Denali park, but now we are doing very specific fieldwork. We are putting our sensors in the park, and that’s challenging. We are collecting temperature data for the park and we continue to work on that, but we are also using remote sensing to see how the slopes are changing and which are more stable and which are less stable.”

Romanovsky predicts that, ecologically, Denali will adapt.

“The ecosystem is changing, but it’s very adaptive. It’s not rigid like infrastructure,” he says. “There will be some changes in topography and some slopes will slide down, and some rivers could be blocked. With infrastructure, it’s about mitigation, not prevention. And planning new infrastructure.”

What Denali National Park will look like in the future, and what visitor access will be like, are open questions. But there is something comforting in knowing that the mountain itself will still be there in all its grandeur, whether or not we can get close to it, and whether or not we as a species can figure out the conundrum of climate change.

At least, this is the idea I was holding on to on our last morning in the Alaska interior. We had planned to get up and drive straight back to Anchorage, but we noticed that the morning had broken especially clear, without even a wisp of clouds visible.

“Should we try one more time?” I asked my husband as we threw our bags into the trunk of our rental car. Because of the ups and downs of the mountain topography, once you’re inside park boundaries, your first chance to see Mount Denali doesn’t come until about mile 9 on the park road. Time and again, we’d driven up to that point with our fingers crossed, hoping to see it emerge from the surrounding landscape in all its glory. It hadn’t happened.

This morning, however, was our last chance. “Why not?” my up-for-anything husband responded. And so, we entered the park once more and drove down the road, past the crowded visitor center and bus depot, filled with people as hopeful as we were.

As we crested a small hill around mile 9, we held our breath.

At long last, and so worth the wait, there it was.

Mount Denali in all its glory

Mount Denali in all its glory, the tallest peak in North America. / Kim O'Connell

Science coverage from around the National Park System is made possible in part thanks to support from Earthjustice.

Other Denali stories of interest from the Traveler's archives:

The Seventymile Kid: The Lost Legacy Of Harry Karstens And The First Ascent Of Mount McKinley

A Day In The Park: Denali National Park And Preserve

Winter Returns To Denali National Park In A Record-Setting Way

Exploring The Parks: When Fall Comes To Denali National Park

A Window To Heaven: The Daring First Ascent Of Denali, America’s Wildest Peak

Rhythm Of The Wild: A Life Inspired By Alaska’s Denali National Park

Photography In The National Parks: Oh, Denali!

Support National Parks Traveler

National Parks Traveler is a small, editorially independent 501(c)(3) nonprofit media organization. The Traveler is not part of the federal government nor a corporate subsidiary. Your support helps ensure the Traveler's news and feature coverage of national parks and protected areas endures. 

EIN: 26-2378789

Support Journalism about National Parks!

National Parks Traveler is a 501(c)(3) nonprofit.

A copy of National Parks Traveler's financial statements may be obtained by sending a stamped, self-addressed envelope to: National Parks Traveler, P.O. Box 980452, Park City, Utah 84098. National Parks Traveler was formed in the state of Utah for the purpose of informing and educating about national parks and protected areas.

Residents of the following states may obtain a copy of our financial and additional information as stated below:

  • Florida: A COPY OF THE OFFICIAL REGISTRATION AND FINANCIAL INFORMATION FOR NATIONAL PARKS TRAVELER, (REGISTRATION NO. CH 51659), MAY BE OBTAINED FROM THE DIVISION OF CONSUMER SERVICES BY CALLING 800-435-7352 OR VISITING THEIR WEBSITE WWW.FRESHFROMFLORIDA.COM. REGISTRATION DOES NOT IMPLY ENDORSEMENT, APPROVAL, OR RECOMMENDATION BY THE STATE.
  • Georgia: A full and fair description of the programs and financial statement summary of National Parks Traveler is available upon request at the office and phone number indicated above.
  • Maryland: Documents and information submitted under the Maryland Solicitations Act are also available, for the cost of postage and copies, from the Secretary of State, State House, Annapolis, MD 21401 (410-974-5534).
  • North Carolina: Financial information about this organization and a copy of its license are available from the State Solicitation Licensing Branch at 888-830-4989 or 919-807-2214. The license is not an endorsement by the State.
  • Pennsylvania: The official registration and financial information of National Parks Traveler may be obtained from the Pennsylvania Department of State by calling 800-732-0999. Registration does not imply endorsement.
  • Virginia: Financial statements are available from the Virginia Department of Agriculture and Consumer Services, 102 Governor Street, Richmond, Virginia 23219.
  • Washington: National Parks Traveler is registered with Washington State’s Charities Program as required by law and additional information is available by calling 800-332-4483 or visiting www.sos.wa.gov/charities, or on file at Charities Division, Office of the Secretary of State, State of Washington, Olympia, WA 98504.
Featured Article
Highlighted