Riverine habitats and associated wetlands form a life-sustaining mosaic throughout the Jackson Hole area. These streams and waterbodies are fed annually by melting snowpack and supply high-quality water that sustains vital watersheds and world-class fisheries. Mountain streams, glacial lakes, willow swamps, marshes, and spring creeks braid together to form the main stem of the Snake River, which is joined by the Gros Ventre and Hoback Rivers. Each of these aquatic and wetland habitats independently and collectively supports a unique array of plants and animals that interact with biological communities. In these wetlands, four targets were identified.
Beaver populations in Grand Teton National Park have declined by over 80% in the last 40 years, including a 25% decline between 2006 and 2011. The causes are unknown, but trapping and changes in backwater channels and ponds are possible explanations.
Cottonwood galleries provide habitat for a variety of birds and bats; an estimated 30% of this forest type between the Jackson Lake Dam and Moose has been degraded since the 1950s. Human controlled flooding events may prevent these trees from germinating properly, preventing new tree growth.
A survey of Flat Creek found that upstream from the fish hatchery, snake river cutthroat trout greater than five inches in length had declined from 191 per mile in 2002 to 58 in 2008, while non-native brook trout increased from 18 per mile to 122. Whirling disease, an introduced pathogen that was first detected in Wyoming the 1980s, is another high-danger threat for this flagship species.
Hydrological processes of the Upper Snake River and its associated wetlands, vital to determining where habitat-sustaining plants will grow, have already been constrained significantly by Jackson Lake Dam and 22 miles of levees from Moose to Hog Island.