The Zumwalt Prairie is the largest remaining areas of Pacific Northwest bunchgrass prairie in North America. These grasslands once covered a vast area west of the Rocky Mountains, and included portions of southern British Columbia and Alberta, eastern Oregon and Washington, Northern Idaho, and Western Montana.  Located in in Wallowa County in northeast Oregon, this grassland once covered approximately 300,000 acres (130,000 ha) of which approximately 20% has since been converted to crop agriculture. Once part of the homeland of the Joseph Band of the Nez Perce people, this area now is used for growing wheat and as spring, summer, and fall range for beef cattle. Despite centuries of human use, the Zumwalt Prairie continues to provide a home for virtually all the plants and animals that have survived here for millennia and supports the largest known population of Spalding’s catchfly (Silene spaldingii).

Recognizing the conservation importance of these grasslands, The Nature Conservancy purchased several parcels on the Zumwalt Prairie (totaling approximately 36,000 acres or 15,000 ha) to ensure their protection through exemplary land stewardship. The Zumwalt Prairie Preserve and Clear Lake Ridge Preserve are managed for conservation, focusing on developing sustainable livestock grazing practices, restoring the fire cycle, and abating the threat posed by invasive plant species.

Because the biodiversity and ecology of this area is relatively poorly known, the Conservancy has invested heavily in science at this site and collaborates with government agencies and universities to better understand how human actions affect the natural systems and the ecological services they provide.