Climate Change

The expanse of Sperry Glacier that once greeted hikers facing NE on Comeau Pass is in stark contrast to the bedrock and vegetation that has since emerged as the ice retreated. The Marble image, most likely taken in the 1920s or early 1930s, was featured on a postcard with this caption: " Sperry Glacier from the river."

The northwest portion of Sperry Glacier once spanned Comeau Pass to the base of Edwards Mountain.

Shepard Glacier from Pyramid Peak, Glacier National Park.

Shepard Glacier in Glacier National Park. The red line on the 2005 image illustrates glacier retreat from 1911 to 2005.

Sexton Glacier from bench below Siyeh Pass, Glacier National Park.

Piegan Glacier is one of the few glaciers in Glacier National Park that has not significantly changed since photographed in the 1930s.

Although the 2009 photo location does not exactly match the historic photo station, a comparison of relative glacial coverage can still be made. Logan Glacier is in the foreground, while Red Eagle Glacier sits beneath the pyramidal peak that bears the same name. It appears that these two glaciers were joined at the time the historic photo was taken, but recessed into their own basins as time...

At the time this historic photograph was taken in 1911, Blackfoot Glacier encompassed the current Jackson Glacier. By 1939, Blackfoot Glacier's recession had resulted in two distinct glaciers, Jackson and Blackfoot. This photo pair shows glacial recession and successive vegetation growth along Jackson Glacier's terminus.

Iceberg Glacier in Glacier National Park.

While difficult to quantify, this photo pair of Harrison Glacier exemplifies the loss of glacier volume. Comparison of the ice profile in the foreground of the photos shows a marked thinning of the glacier over the years,. Colorful layers of sedimentary bedrock are being exposed as the glacier recedes from the cliff bands.

As Grinnell Glacier retreats, vegetation establishes itself in the newly exposed surfaces. The increase in vegetation along the moraine (center) in this pair is especially obvious.

Upon close inspection of this photo pair, the viewer can appreciate the change in the volume of glacial ice that has melted from Grinnell Glacier. In the 2010 image, the glacier's terminus can be seen along the edge of Upper Grinnell Lake, a feature that did not exist in 1936.