top of page

Spotlight: Climate Change in Montana's National Parks

In the mid-1990s, Lisa McKeon was working as a physical scientist at Glacier National Park when she happened to compare a modern-day glacier photograph with one taken almost a decade before. McKeon was shocked to see the gigantic chunks of ice on Glacier National Park’s towering mountaintops melting to sparse patches of snow.

The Montana-born physical scientist moved back to Montana in 1997, after conducting field studies at Yosemite and Sequoia National Parks. Her work monitoring back-country weather stations and on-the-ground wildlife research gave her a good frame of reference for studying the ecosystem at Glacier. In her first year conducting research at the park, McKeon was introduced to repeat photography.

“Repeat photography is when we find a historic photo that was taken on the ground, then we try to relocate the exact spot and take the same picture,” McKeon says.

In the early 1930s, a glaciologist named George Dyson was already using photographs to depict a decline in the glaciers in the national park. McKeon’s team of USGS scientists used developing technology to take the concept of repeat photography a step further. They used global positioning systems and digital photography to align the landscape so that one image appears to dissolve into another.

Glacier National Park’s repeat photography collection was one of the first nationally to capture the public’s attention. Scientists introduced them when Al Gore came to visit the park in October, 1997. Gore, who was serving at the time as vice president in the Clinton Administration, called the glaciers the most tangible illustration of global warming. Scientists had compiled an assortment of data and statistics for the public and media but it was the photographs that drew the most attention.

Even in the late 1990s, the project unmasked some shocking revelations about just how much Glacier was changing. McKeon says she quickly recognized the value of repeat photography in the park and began to coordinate an effort to retake as many historic pictures of the glaciers as possible.

In the past two decades, McKeon and the her USGS colleagues at Glacier National Park have amassed a collection of 750 historic glacier photos. They have re-photographed more than 75 of these images, documenting changes at 20 different glacier sites.

Today, the photos continue to illustrate the impacts of a warming climate.

When Glacier National Park was established in 1910, the park contained more than 100 glaciers. Now, only 26 meet the size criteria to be designated as active glaciers and the ice is melting quickly.

“People who have visited here in the 1960s or 1970s will come back and be absolutely shocked because they remember this huge glacier – and now there’s just this little patch of ice left,” says Dan Fagre, the lead USGS climate scientist at the park.

“We are basically looking at the last stages of these glaciers. They are just about to wink out,” Fagre says.

The unique high-alpine environment of the park makes it susceptible to small changes in temperature, leading to dramatic changes in the landscape. Fagre says the rate at which the glaciers are disappearing is startling.

“You can see things you would expect to see occurring over hundreds of years occurring in just decades,” Fagre says. “The glaciers are all disappearing at different rates, depending on their position on the mountain landscape, but all of them are losing, and it’s just a matter of time.”

The Cause? Heat Trapping Gases

Burning fossil fuels adds heat-trapping gases to Earth’s atmosphere. According to, climate change refers to a broad range of global phenomena created predominantly by the increase of man-made carbon dioxide in the atmosphere.

HOW TO MEASURE CLIMATE CHANGE: Burning fossil fuels adds heat-trapping gasses to Earth’s atmosphere. As gasses in the atmosphere increase, the temperature of the planet also increases. Evidence of warming can be found in a variety of global indicators. Like many science-based institutions, the World Meteorological Organization (at right) uses a list of climate indicators drawn from a Global Climate Observing System. Indicators such as surface temperature, ocean heat content, atmospheric carbon dioxide and even glacial activity are measured across many regions and ecosystems on Earth. The data from all of these indicators is then used to asses the health of the climate and the shifting climate trends as a whole. An isolated June snowstorm in Montana, for example, does not negate a pattern of global warming. The storm is just one incident within an indicator (precipitation) in one region of a complex global climate system. Advancing indicators of warming, such as a rise in global mean temperature across the planet, continue as human influence increases gasses in the atmosphere.

Climate change includes the increased temperature trends described by global warming and also encompasses changes such as sea level rise and ice mass loss in Greenland, Antarctica, the Arctic and mountain glaciers worldwide. Impacts of warmer climates also include shifts in animal migration, the timing of plant blooming and insect hatches, and a rise in the frequency of extreme weather events.

The National Park Service initiated a global change research station at Glacier National Park in 1991. Fagre started working at the park that same year and remains in his position as a research ecologist and Director of Climate Change in the Mountain Ecosystems Project. He, McKeon and a handful of other USGS scientists research and document the multitude of impacts that climate change is having in Glacier. They also contribute to a network of scientists across the globe, including the University of Vienna in Austria, to better understand how mountain ecosystems respond to climate change.

Mountainous areas are changing more quickly than most landscapes because just a few degrees in temperature change, between 29 and 33 degrees Fahrenheit for example, is the difference between whether precipitation falls as rain or snow.

“Snow accumulating for six or seven months creates a huge reservoir of water that’s hanging out up in the mountains,” Fagre says. “When summer comes, the snow melts into water, feeding rivers and irrigating farmlands.

“But if the weather warms up just a few degrees and falls as rain, it runs off the mountain instead of creating a reservoir for those hot summer months,” he adds. “Places that are hundreds and thousands of miles away are affected by whether the mountains hold snow or don’t hold snow based on a tiny temperature change. It creates a complete overhaul on all of these systems.”

Changing Systems

More than one hundred years ago, the glaciers held enough water to feed major rivers and lakes across the Flathead Valley, Dan Fagre says. Now they only contribute a fraction of the water that goes into the major rivers and lakes.

When the winter snowpack is gone and rivers run the risk of getting too low and hot for fish to survive, water melting from glaciers acts as a “safety valve” by continuing to provide the ice-cold water high-alpine species are adapted to.

“We have many endangered stream insects that will likely disappear if the glaciers disappear and the snow packs continue to dwindle, and it becomes a hotter, drier environment,” Fagre says.

The scientist adds that the rise in temperatures in mountainous areas will likely be perilous to plants and animals adapted to living in the highest parts of the mountains, the habitat above the tree-line.

“There have been studies over the past hundred years that have found when temperatures increase, both plant and animal species move up slope – they move higher and higher up the mountain. Ultimately, when you get to the top, there’s nowhere else to go,” he says.

“You can’t migrate to a different place. So a lot of these mountain areas become the last refuge for certain species,” Fagre says. “It’s a concern if those last refuges are heating up.”

One species especially vulnerable to this effect is the endangered bull trout, a fish that needs cold, connected habitats for their growth and survival. Another species impacted by climate change is the White Bark Pine tree, which provides a vital high-calorie food source for grizzly bears and other wildlife.

Among dozens of threatened plants and animals, the changing climate also has affected the snowshoe hare. The hare’s coat used to camouflage it from predators by turning from white to brown with the change of seasons. But a shorter winter season has made the snowshoe hare stand out.

“The timing when they turn color is obviously very important because if you are all white in a brown background you are very easy to spot by predators,” Fagre explains. “That’s an example of how climate change is not always illustrated by a rise in temperature. Sometimes it’s the timing that’s also important. It can change the way seasons stop and start and that can have an impact on some animals.”

An Unstable Environment

Glacier National Park Superintendent Jeff Mow says he has made some hard decisions in the past about how to respond to climate change while managing national parks in the United States.

“The National Park Service is not a research organization; we are a land management agency,” he explains. “As a result, what we really look at is the response to climate change. Climate change can bring changes to infrastructure: our roads, our bridges, our trails.”

Before coming to Glacier, Superintendant Mow managed Kenai Fjords National Park in Alaska, a park containing nearly 40 glaciers flowing from the Harding Icefield. While Mow was managing the park, a strange phenomenon occurred.

“In the middle of summer, when it wasn’t cloudy and rainy, the roads were flooding. That was something we had never observed before. And it was literally glacier melt that was driving that,” Mow says.

Mow explains that his park managers found a lot of the infrastructure designed for the park in the 1980s, when he says the glaciers were still pretty stable, was becoming obsolete.

“It brought about this philosophical thinking,” Mow says, “Because things are changing around us so quickly, how can we be more adaptable and flexible in the face of change?”

Climate change may also be influencing seasonal visitation trends at Glacier, he says. Visitation numbers are at an all time high at the park but the time of year people come to visit the park is changing. Glacier had a record number of park visitors in 2017 and 2018 was the second busiest year for the park, despite parts of the park being closed by wildfires during the summer season.

The bulk of the visitation now occurs in the shoulder season, Mow says. More and more visitors avoid the historically busy months of July and August, instead visiting the park in spring and fall.

“In May and June 2018 we saw double-digit increases in visitation, as well as increases in October and November,” Mow says.

Historically, a good snowpack would have an influence on water levels in rivers and lakes throughout the summer. It could also indicate a milder fire season as melting snow would provide moisture late into the summer.

Even though winter snowfall was more than average during in the past few years, Glacier was struck by destructive summer wildfires. The Sprague fire forced a closure of a large portion of the park and charred the historic Sperry Chalet in the summer of 2017. The following summer, a wildfire destroyed historic structures, forced the evacuation of the Lake McDonald area and closed Going-to-the-Sun Road during parts of August and September.

“What we have seen more recently is wildfires that have nothing to do with snowpack anymore,” Mow explains.

“More recently the bulk of the snowpack is gone by early to mid-June. Wildfires now are pretty much driven by how hot and dry it is in the months of June and July,” Mow said.

Advocating for Glacier

Retired math teacher and Whitefish resident Randy Carspecken moved from Wisconsin to work at Glacier National Park in 1974.

“I remember suddenly coming into these great mountains and huge valleys and becoming struck by the mountain vistas,” Carspecken says. “Glacier just spoils you.”

At age 20, Carspecken fell in love with Glacier National Park. Soon after, he also fell for Dawn Cope, a young woman who left home to work at the national park. The two adventurers bonded over their common passion for the wilderness by hiking in the pristine alpine environment.

Forty-four years later, the Whitefish couple is still together, and they still frequent the park together, but they avoid Glacier during peak times of the year because the traffic has become too much for them.

“We locals stay out of the popular places in the park in the high season,” he admits.

“Besides the shrinking glaciers in Glacier Park, one of the more imagination-grabbing changes in the last 45 years is the drastic increase in tourism right in your face.”

The longtime park visitor says he thinks the employees of the National Park Service have done a good job protecting the backcountry from overuse with an adequate permitting system, but he sees them struggle to manage traffic along the main thoroughfares.

“The number of vehicles is staggering,” he says. “The shuttle system has helped, but the average visitor in high season is typically stuck in traffic and has a hard time finding parking along the iconic Going-to-the-Sun highway.”

Ironically, he notes, the publicizing of the shrinking glaciers likely promotes more tourism.

Communicating Climate Change

Melissa Sladek, a science communicator for the Crown of the Continent research center at Glacier National Park, says most visitors who come to the park realize that the glaciers are melting.

“People know they may be gone soon and they want to see them,” Sladek says. “That is a very typical mindset for visitors. Some people say ‘Oh, that’s sad,’ or ‘That’s too bad.’ But what does it actually mean?” she asks. “We have to focus on what it means to our communities.”

More than half of the world’s freshwater supply comes from mountain run-off in the form of rain, melting snow and ice. In Western Montana, mountains account for anywhere from 60 to 80 percent of the water supply.

Less snowpack, snow melting off the mountains earlier each year and the loss of the cold water back-up historically provided by glacial runoff, may well impact farmers who depend on irrigation, deplete drinking water supplies and change the way we recreate in the future, Sladek says.

Because the impacts are so striking, Sladek says she encourages Montanans to talk with one another about climate change.

“Change can be really hard for people, seeing how the landscape is changing and seeing how we have to change and adapt,” she adds. “But we are already adapting. People are realizing that there is a lot we can do and there is a lot that we are doing.”

Nature’s Alert System

At Glacier, nearly all of the scientific research being done addresses climate change, either directly or indirectly. The research helps park managers make management decisions and adapt new strategies to help them be flexible in an uncertain time. The USGS scientists are joined by visiting scientists, including researchers from universities. Several local conservancies and nonprofit organizations also work to support Glacier National Park with fundraising, education and outreach.

“There are definitely a lot of people working together to take care of the park,” USGS climate scientist Dan Fagre says. Fagre hopes individuals are alert to what the research is indicating regarding climate change.

“Anytime a red flashing light is going on that warns you that something is not right, you should pay attention to it. Whether it is on your car dashboard or whether it’s glaciers melting in the mountains,” he explains.

“We all depend on water and mountains provide a huge percentage of the water that humans consume, particularly in the western United States, where in some cases 100 percent of your water is coming from mountains,” Fagre continues. “If your mountains are no longer going to act as those reservoirs – and glaciers are giving us an indication of that – you are going to have some degree of upending society. It doesn’t matter who has the rights to water if it’s not there. You are going to hurt.”

Long-time visitor Randy Carspecken has become a Glacier Park advocate. He says environmental issues have been on his mind since the first Earth Day in 1970. He remembers checking out a book, “Ecology” in high school in the early 1970s. The book explored a relatively new concept: the need for balance in the natural world.

“Then, some decades ago, we came to find out that human influence is really having a big hit on the earth. I don’t think it comes as a surprise to most of us,” he says. The former math teacher says he wants to put forth a more focused effort toward living a sustainable lifestyle in his retirement. He now serves as a board member for Climate Smart Glacier, a group that aims to help local communities find resilience in the face of climate change.

Carspecken said he realizes tackling an issue as big as climate change can be daunting.

“It can feel like pushing a rock uphill, and the rock keeps rolling back down,” he says. “We all at times feel that way because it is such a big undertaking.”

Carspecken insists, however, that putting in an effort to combat climate change on any level is worth it, and that Glacier National Park is a place worth preserving. Even though Carspecken has seen changes in Glacier National Park’s environment over the past few decades, his love for the park continues to this day.

“It is a relatively small park but so much is packed into this place,” he says.

Carspecken and his wife recently reunited with friends to reacquaint themselves with the Glacier backcountry campsites at Stoney Indian Lake and Mokowanis Lake.

“We had almost forgotten about all of the waterfalls and how the mountains rise up so spectacularly, surrounding you in such a unique way,” recalls Carspecken. “I don’t think there’s any other place quite like it.”

—Breeana Laughlin

Recent Posts

See All


bottom of page