The Nature Conservancy’s Sweetwater River site contains significant natural habitat for plants and wildlife, as well as Native American cultural sites and portions of the Oregon, California, Mormon Pioneer, and Pony Express historic trails. The project area includes 21 miles of the free-flowing Sweetwater River, one of Wyoming's most extensive and intact high desert riparian areas. Along the river, dense stands of native willow provide cover for numerous mammals and birds. Dry grasslands populated with big sagebrush extend for miles upland of the river.
Central Wyoming, near Lander.
The project area includes 2,305 acres of Conservancy land (encompassing 6 river-miles) and more than 2,300 acres of private land protected by conservation easements and deed restrictions. In addition, nestled between these parcels is a 5,900-acre Bureau of Land
The project area contains large occurrences of riparian willow and herbaceous communities which support an abundance of native plants, including the rare meadow pussytoes (Antennaria arcuata). Herbaceous meadows transition to Wyoming big sagebrush and mountain big sagebrush communities in the uplands.
No plant defines the West more than sagebrush, which sports silvery-gray foliage and pale yellow flowers. Known for its pleasant aroma, sagebrush is an important plant for many songbirds, sage grouse, and big game animals.
Pronghorn antelope often are seen on the surrounding sagebrush flats. Moose forage along the river, where mule deer, elk, porcupine, and beaver also can be found. White-tailed prairie dogs occasionally poke up their heads from burrows, wary of golden eagles, red-tailed hawks, prairie falcons, and other raptors. Sage grouse, white pelicans, sandhill cranes, great blue herons, killdeer, and mountain bluebirds commonly live here during the summer.
Why the Conservancy Selected this Site
The Sweetwater River is one of the most intact examples of a middle-elevation riparian system remaining in Wyoming. The Conservancy began working in the area in 1991 in order to prevent the habitat fragmentation that typically accompanies subdivision, to better control livestock grazing in the riparian corridor, and to protect the abundant native plants and animals in the area.
What the Conservancy Has Done/Is Doing
When TNC acquired the property, riparian under stories were dominated by non-native plant species, and willow regeneration was all but absent. For brief periods during fall, and occasionally during spring, cattle graze the project area. They are part of a carefully monitored program to encourage the growth of native plants that require periodic grazing to thrive. Until the 19th century, bison filled this niche. Now, the Conservancy is using cattle to improve conditions for native plants.