Thunder Basin National Grassland spans a protected semi-arid landscape in northeastern Wyoming's Powder River Basin, between the Big Horn Mountains and the Black Hills. Set between the Great Plains and the sagebrush steppe, it supports a mix of grassland and sagebrush communities shaped by drought, grazing, fire, and burrowing mammals. Its intermingled federal, state, and private lands complicate management and access. Wildlife is a defining feature, including more than 100 bird species, pronghorn, mule deer, swift fox, and prairie dogs, whose colonies provide key habitat for species such as mountain plover. Grazing, dispersed recreation, and recent ecological change underscore both the grassland's working character and its fragility.