Visions of Alaska often include stunning wildlife, majestic peaks, and the brilliant glaciers that hug the mountains. But in Wrangell-St. Elias National Park and Preserve, the foot of Kennicott Glacier might go unnoticed, hidden beneath miles of dirt and rock called glacial till.

The retreat of glaciers in Alaska, like Kennicott, can be explored in a story map produced by the National Park Service. The site features maps, measurements, and videos that show how glaciers across the state have changed since the middle of the 20th century.

Maps and measurements show changes to Kennicott Glacier in Wrangell-St. Elias National Park.

“There’s so much ice in Alaska that when all those glaciers shrink a little, not to mention a lot, it adds up to some really big changes. I would like to see people cognizant of the magnitude of the changes that are occurring in the state already,” Dr. Michael G. Loso, previously with Alaska Pacific University and now a physical scientist at Wrangell-St. Elias, said in one of the videos featured on the site. “Even people who worry about climate change worry about 2050 or 2100. What’s going to happen? And I think a big part of the message here is, it’s happening.”

Glacial change has consequences for factors such as sea-level rise, changes in the runoff in rivers, and effects on fish habitat.

Nine of Alaska’s 15 national parks, preserves, and monuments contain or adjoin glaciers. The story map hones in on 18 glaciers. Maps display the modern reach of each glacier, along with an orange overlay of the historic extent. To show the retreat, the team mapped all glaciers in nine parks for two time intervals:

• The mid-20th century, generally between 1951 and 1960, with U.S. Geological Survey topographic maps
• The early part of the 21st century, between 2004 and 2011, using the most recent satellite imagery available

These maps and images were then digitized to show the glaciers’ footprints for both periods and compared to determine the extent of change. They then combined that information with laser altimetry data to attempt to measure the volume of each glacier and how it has changed over time.

“Wrangell-St. Elias, to me and to a lot of people, really is about the glaciers. There’s no other place that has the kind of ice that we do,” Dr. Loso said. “When you talk about taking that away, watching those glaciers shrink, it really sort of strikes at what for some people is the heart of what this park is about.”