Glacier National Park was named for its small active glaciers. Indigenous People have referred to the Glacier National Park area as âÂÂthe place where there is a lot of ice.â Other Tribes describe the park as âÂÂthe land of the shining mountainsâ because of the bright, reflective snow and ice seen from the plains to the east.
The earliest known mention of the parkâÂÂs name is found in a 1906 exchange between George Bird Grinnell and glacial geologist, François E. Matthes. He wrote, âÂÂthe park proposed would contain roughly 1500 sq. miles, containing upward of 50 ice-bodies and over 200 lakes. It might fitly be called Glacier Park.âÂÂ
Once Glacier National Park was established in 1910, the US Geological Survey (USGS) began sending William C. Alden on annual expeditions into the park to survey and map the parkâÂÂs glaciers and topography. In 1914, USGS published AldenâÂÂs report, The Glaciers of Glacier National Park. The first sentence of the report reads, âÂÂGlacier National Park derives its name and much of its interest from the presence of many small glaciers.âÂÂ
The park contains dozens of bodies of ice, some that meet technical definitions of a glacier and some that do not. At least 35 of these ice bodies are officially named. Counting the number of glaciers requires defining which ice body deserves to be called a glacier. The USGS defines a glacier as a body of ice with an area of at least 0.1 kilometers<sup>2</sup>. "Below this size, ice is generally stagnant and does not have enough mass to move.âÂÂ
A 2019 study calculated that in the late 1800s, at the end of the Little Ice Age, there were 82 bodies of ice larger than 0.1 kilometers<sup>2</sup>. If the definition of a glacier was expanded to 0.01 kilometers<sup>2</sup> then there were 146 glaciers. The same study counted 34 glaciers larger than 0.1 kilometers<sup>2</sup> in the year 2005.
A 2017 data release by the USGS counted the decline of named glaciers in the park. At the end of the Little Ice Age there were 35 glaciers (that are today officially named), in 1966 those same 35 remained, in 2005 seven had shrunk below 0.1 kilometers<sup>2</sup>, leaving 27, and by 2015 there were 26 named bodies of ice large enough to be considered glaciers.
In 2003, researchers published an academic paper about two of the park's glaciers in the Journal of BioSciences. They used a geospatial computer model to predict the advance or retreat of Blackfoot Glacier and Jackson Glacier for each decade from 1990 to 2100 based on melting rates from historical data.
Since Blackfoot and Jackson are relatively large glaciers, some experts hypothesized that if those two glaciers were completely melted then all the other glaciers in the park likely would be as well. A few years later the researchers looked again at how fast Blackfoot and Jackson were shrinking and found that they seemed to be melting faster than they first predicted. Informally, the researchers moved their 2030 date up to 2020.
These predictive dates spread widely and were featured on various exhibits around the park. As 2020 approached, and scientific understanding of glacial melt advanced, the 2020 and 2030 prediction dates were removed.
A 2010 study estimated the rate of disappearance of one of the park's glaciers, Sperry Glacier. That study found that for each degree of global warming the glacier would disappear faster. The authors wrote, âÂÂunder the most probable temperature increase...we conservatively estimate the glacier persisting through at least 2080.âÂÂ
The USGS started a Repeat Photography Project in 1997. The project collected historic photos of the park's glaciers and then took new photos of the glaciers from the same vantage.