Area 126 covers the country east of Gillette including the Black Thunder area and the country running toward the South Dakota line—open Powder River Basin prairie dominated by surface coal mining and coal-bed methane operations. Elevations run from about 4,200 feet on the basin floor to 5,500 feet on the higher prairie ridges. The country is wide-open: big sagebrush and bunchgrass on the flats, scattered ponderosa pine on the breaks, and the immense Black Thunder coal mine—at one point the largest single coal mine in the world by production—which dominates a big chunk of the country. Cottonwood-and-willow creek bottoms run through the Belle Fourche River drainage. The country is functionally industrial in places and surprisingly empty in others; the surface mines occupy permitted blocks while the surrounding prairie remains huntable. BLM, state trust, and significant private ranch and mining holdings share the country. The HMA and Walk-In programs add access. WY-450 and I-90 frame the access; lease and mine roads thread the rest. Gillette is the full-service supply hub. Cell service is fair throughout. Antelope on the open prairie is the headline; the country holds strong pronghorn density and the sheer scale of the basin means there's room to spread out. Mule deer in the breaks; whitetail in the creek bottoms. Mine traffic is constant—respect the haul roads, do not enter active permit areas without authorization.