Repeat photo pair documenting shrinking glaciers near Chilkoot Pass. Upper image is composed of five images made in 1906 by George R. White-Fraser of the International Boundary Commission (National Archives of Canada PA-162903, PA-162902, PA-162894, PA-162895, PA-162901). Lower image made August 5, 2014 by Ronald D. Karpilo Jr. and Sarah C. Venator (NPS).

How have the landscapes and natural features around Skagway and Dyea, Alaska changed in 115 years?

National Park Service geologists Ron Karpilo and Sarah Venator recently completed the field portion of a repeat photography project attempting to answer that question. Using more than 80 historic images, some dating back to 1894, the researchers documented and interpreted 20th century changes to glaciers, streams and vegetation. Historic photos were repeated in exact locations in Skagway, the White Pass, and the Dyea and Chilkoot Trail Units.

Repeat photo pair documenting vegetation and glacier changes visible at Rocky Point on the White Pass and Yukon Route Railroad. Upper image was made August 1899 by Harrie C. Barley (Yukon Archives, H.C. Barley fonds, #5509). Lower image was made August 3, 2014 by Ronald D. Karpilo Jr. and Sarah C. Venator (NPS).

The most notable changes observed in the repeat photo pairs include: glacial retreat, plant succession, vertical advance of tree lines, and significant regrowth of vegetation in the Taiya River Valley after former glacial outburst floods scoured the valley floor. The glaciers have visibly retreated and thinned during the past century. In most areas, the tree line has advanced upslope, the density of vegetation in valley bottoms has increased, and glacial moraines have become vegetated.

Assistance from the park staff and collaboration with the White Pass & Yukon Route Railroad and Parks Canada were critical to the success of this project. The photo pairs produced by the project are available for educational purposes, resource management, and research.

For more information, please contact: Sarah Venator ([email protected]), or Ron Karpilo ([email protected]).