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Glaciers Then & Now

Glacier National Park's Disappearing Namesake

brandon · Jun 7th, 2017

Glacier National Park

Glaciers

When Glacier National Park was founded in 1910 it had roughly 150 glaciers – now it has 25 [1]. In the past 50 years, the remaining glaciers have shrunk in area by over a third [2].

Repeat Photography

When historic and modern photos of the glaciers are compared side-to-side the differences are striking. Repeat photography is one technique the USGS uses to document the differences between glaciers over time. They are also looking for volunteers to help out with this project.

Glacial Timeline

Pleistocene Ice Age (1.9 million years ago to 12,000 years ago): During the Ice Age, snow and ice covered all but the highest peaks of Glacier National Park. [3] At the end of this period all of the glacial ice in the park melted out which had a profound impact on shaping the landscape around the park.

7000 years ago: The glaciers began forming.

Little Ice Age (1400 - 1850AD): Although the cause is not certain, from 1400 to 1850 the earth cooled drastically and the glaciers of Glacier National Park grew substantially. Most of the ice existing today is from this period. The causes of the Little Ice Age are not known for certain but some theorize that it was a result of reduced solar output or increased volcanism.

Industrial Revolution Until Now (1850 - now): Since 1850, the glaciers have been shrinking. Models predict that most of the glaciers could completely melt by as soon as 2030. [4]

The Little Ice Age comprised a several-hundred-year-long cool period (about 1400 to about 1850 in North America), during which Glacier National Park glaciers formed and expanded. This continued until a warming climate initiated glacier retreat after the middle 1800’s. Because of the apparently long and relatively stable climatic interval preceding the Little Ice Age, it is believed that most of the glacier ice remaining in Glacier National Park was formed during the Little Ice Age and is not a relic from the Pleistocene Epoch

— Carl H. Key, Daniel B. Fagre, and Richard K. Menicke in "Glacier Retreat in Glacier National Park, Montana"

Browsing Glaciers on Natural Atlas

If you want to learn more about how each glacier has melted over time you can now go to its page on Natural Atlas. Some of the most popular glaciers are listed below, or you can click to see a list of all of the glaciers in Glacier National Park.

– The areas that have melted from 1966 to 1994 now show up as red on the map.

– Click on the name of glacier on the map to see historical vs current photos (if available). If you are interested in taking and adding photos, read this guide about how you can help the USGS with repeat photography.

– Each glacier page now has a basic graph showing the reduction in area over time.

(source data: USGS)