ROCK GLACIER DISTRIBUTION AND ENVIRONMENTAL INFLUENCE ON THE BRIDGER-TETON NATIONAL FOREST

The Bridger-Teton National Forest (BTNF) is 3.4 million acres of public land, located within the Greater Yellowstone Ecosystem, which is the largest intact ecosystem in the contiguous United States. The area is an important habitat to many charismatic species such as grizzly bears, Yellowstone cutthroat trout, and whitebark pine. Glaciers provide an important source of cold-water input for streams and lakes, especially in late summer, with direct and indirect benefits to many species. However, rock glaciers—masses of debris-covered ice that actively move downhill—are much more numerous on the BTNF and also represent an important source of cold water to headwater lakes and streams. According to Fountain et al. (2023), there are 15 glaciers and 44 perennial snowfields within the BTNF. In comparison, Johnson et al. (2021) mapped 328 rock glaciers on the BTNF, with 77% of them displaying surface morphology of an actively flowing feature. The debris cover of rock glaciers insulates them from ambient conditions and warming which means they are likely to persist on the landscape longer than “exposed” ice features.

Here, we aim to better understand the distribution of rock glaciers and their influence on downstream habitat in terms of water temperature and quantity on the BTNF. We will measure water availability and temperature of headwater streams draining rock glaciers within the BTNF and compare these data to streams without upstream perennial ice. This information will have management implications for stream restoration prioritization across different watersheds on the BTNF.