Thunder Basin

The Thunder Basin is a grassland stronghold, rich with mixed-grass prairies, where fifty or more plant species may thrive in a two-acre area. These grasses are drought-tolerant and many are well-adapted to large grazing animals. They are also well-matched to the sometimes extreme weather of the high plains and lightning-sparked wildfires help many grass species germinate and reproduce. In some areas, grasslands give way to sagebrush, cactus or woodlands with ponderosa pine, limber pine or juniper.

Thunder Basin tests our tolerance for wide-open spaces. People who don’t live on the prairie may struggle to comprehend the apparent endlessness of a horizon rolling away into a vast, swallowing sea of open sky.

Despite its rich soil, Thunder Basin’s high, relatively cold climate made it generally unattractive to farmers and their furrowing plows that overturned much of America’s Great Plains. As a result, these grasslands contain some of the most intact native prairie left in the United States.

With time, pressures for development on Thunder Basin’s grasslands will continue to mount. Much has already changed since the first European explorers waded through the prairie. Bison that once dominated this landscape are long gone, and many grassland species face an uncertain future.

Here, The Nature Conservancy has joined one of the largest voluntary conservation agreements in recent history. We’ve come together with a broad coalition of partners to finalize a conservation strategy that reaches across more than 13 million acres of the Thunder Basin and northward into Montana.

The agreement protects several species of concern—including burrowing owls, ferruginous hawks, and greater sage-grouse—by avoiding fragmentation or destruction of vital habitat.

Under the agreement, landowners—including livestock producers and energy companies—implement voluntary conservation actions that help wildlife that were headed toward becoming candidates for threatened or endangered species listing. A key partner in the coalition is the Thunder Basin Grassland Prairie Ecosystem Association (TBGPEA).

Life recycled in grassland soils provides nutrients to a wide diversity of animals. Hawks, swift foxes, pronghorn and black-tailed prairie dogs all inhabit Thunder Basin. The black-tailed prairie dog is particularly important for its role in building burrows and other vegetation that create habitats for a variety of species. Many grassland birds migrate from as far away as Mexico and South America to spend part of each year in the Thunder Basin, including the burrowing owl, mountain plover and Sprague’s pipit.

Grasslands are the least protected habitat on Earth. Habitat fragmentation caused by residential development, invasion by non-native plants, coal and coal-bed methane mining and altered natural fire patterns have all taken a toll. Fortunately, the Thunder Basin still contains a vast expanse of intact native prairie—due in part to the stewardship of landowners. As a result, The Nature Conservancy and its partners have a chance to protect this grassland stronghold now, while it still carpets its historic range.

In the Thunder Basin grasslands, federal and state lands intermingle with vast expanses of private lands ownership. One of the largest coal companies in the U.S. is also located here. Cooperation that brings farmers, ranchers and other landowners to the table is the only way we can continue conserving Wyoming’s native grasslands. By combining our efforts with coalitions such as the Thunder Basin Grasslands Prairie Ecosystem Association, TNC is exploring solutions that address human needs as well as conservation priorities.