Morton J. Elrod photographing Chaney Glacier in 1911.
The United States Geological Survey (USGS) started the Repeat Photography Project in 1997 with a systematic search of Glacier's archives for historic photographs of glaciers in the park. They found many images to work with from early photographers such as Morton Elrod, T.J. Hileman, Ted Marble, F.E. Matthes, and others who scoured the park to publicize its beauty and earn their livings. The USGS scientists then hiked the historic images into the field to rephotograph them from the exact same vantage point.
Historically and today, photographing the glaciers can only occur in a narrow window in late August and early September after the previous winter's snow has melted from the ice and before the first snows of autumn. It is only in the late summer season that the glaciers can be clearly seen.
Grinnell Glacier 1910 and 2016
Left image
Morton J. Elrod, K. Ross Toole Archives, 1910
Right image
Lisa McKeon, USGS, 2016
In 1910, Morton Elrod documented how Grinnell Glacier’s mass filled the basin and how the glacier was then joined with the ice apron we now call the Salamander (right). Close inspection of Gem Glacier (top-center) reveals a loss of thickness and volume over the years as well.
Jackson Glacier 1911 and 2009
Left image
Morton J. Elrod, K. Ross Toole Archives, 1911
Right image
Lisa McKeon, USGS, 2009
Although melting glaciers are the most visible indicators of climate change in the mountains, the entire mountain ecosystem is responding. Using both repeat photography and tree-ring studies, scientists have documented that trees are growing faster, becoming taller and filling in the spaces in between trees. Young seedlings have established and are surviving in areas where deep snowpack and harsh weather conditions had previously excluded them. How do you think this vegetation change will impact wildlife?
Blackfoot and Jackson Glacier 1914 and 2009
Left image
E. C. Stebinger, GNP Archives, 1914
Right image
Lisa McKeon, USGS, 2009
Jackson Glacier was once part of Blackfoot Glacier, one of the largest glaciers in the park. By 1939 the expanse of Blackfoot Glacier had receded and separated into two distinct basins, giving rise to the separate names of Jackson and Blackfoot glaciers. Along with the glacial recession evident from this pair, can you pick out another big change?
Boulder Glacier 1932 and 1988
Left image
George Grant, GNP Archives, 1932
Right image
Jerry DeSanto, K. Ross Toole Archives, 1988
This is one of the earliest photographs repeated from the park that shows the disappearance of glacial ice. It helped to start the current Repeat Photography Project. The 1932 photograph shows a guide, wearing chaps, and three clients next to the ice cave. This was one of the popular multiday routes during the heyday of horseback trips through the park and underscores the charisma that glaciers had for early park visitors. Boulder is now too small to be considered active.
Sperry Glacier 1930 and 2008
Left image
Morton J. Elrod, K. Ross Toole Archives, 1930
Right image
Lisa McKeon, USGS, 2008
Repeating Elrod’s 1930 photograph from the exact spot was impossible since it was shot from the elevated surface of the now receded glacier. The terminus of the glacier has retreated beyond the field of view, but these images give a sense of the glacier’s extent and mass early in the twentieth century. Sperry Glacier is a benchmark glacier for USGS scientists. Scientists use its measurements of annual change as a baseline to compare with other glaciers and to predict future changes.
Shepard Glacier 1911 and 2005
Left image
Campbell, USGS, 1911
Right image
Blase Reardon, USGS, 2005
Shepard Glacier is now less than 25 acres in size and is therefore no longer considered an active glacier. As the park's glaciers melt, the effects will be felt far downstream. Glaciers store about 70% of the world’s freshwater. They regulate stream temperatures and maintain stream flow during late summer and drought periods when other sources are depleted. Without glacial meltwater, summer water temperatures will increase and may stress temperature sensitive species, such as aquatic insects and native trout.
Thunderbird Glacier 1907 and 2007
Left image
Morton J. Elrod, GNP Archives, 1907
Right image
Dan Fagre, USGS, 2007
Acquiring the 2007 photograph of Thunderbird involved some serious scrambling on cliffs and made USGS scientists admire Morton J. Elrod, the original photographer, who carried much heavier and bulkier gear over the same terrain. Using arial imagery, scientists know that Thunderbird melted from 33 acres in 1966 to 26 in 2015, a loss of 21%, putting it very close to the inactive cutoff of 25 acres.