MONITORING GLACIAL RETREAT IN THE WIND RIVER RANGE (BRIDGER-TETON NATIONAL FOREST)

As climate changes, most glaciers around the world continue to retreat, including the ice masses of Wyoming's Wind River Range. The disappearance of these resources will impact the ecosystem services provided by the Bridger-Teton National Forest (BTNF), a noticeable example being a decrease in late-summer flows reaching Sublette County, an area with a large amount of agricultural development. A step in understanding if and how forest service management practices should be adjusted in response to this change is to survey the current state of the glaciers, understand their contribution to the Upper Green River and, over time, determine their rate of change. Glaciers with the most average characteristics for the mountain range chosen for the program and are done so using a weighted scale taking into account aspect, elevation and size. Accessibility and risk level are also taken into account when selecting glaciers for the program. Mammoth Glacier near Gannett Peak was chosen as the main focus of this study with the possibility to extent the program to Sourdough glacier in the near future. Rate of change is measured through monitoring changes in surface elevation of the glacier, collected using a high accuracy GPS to collect elevation points while walking up the glacier, as well as by observing changes in extent of the glacier, and changes in the equilibrium altitude line (ELA) using satellite and aerial imagery. Water quality and quantity from glacier runoff downstream are measured in Wells Creek and in the Green River above their confluence and below the confluence.

The Greater Yellowstone Coordinating Committee (GYCC) recognizes the importance of glacial retreat and has taken steps to implement a systematic glacier monitoring program across the larger ecosystem.