Bad Lands, Badlands(noun)

an eroded and barren region in southwestern South Dakota and northwestern Nebraska

Bad lands(u)

barren regions, especially in the western United States, where horizontal strata (Tertiary deposits) have been often eroded into fantastic forms, and much intersected by ca–ons, and where lack of wood, water, and forage increases the difficulty of traversing the country, whence the name, first given by the Canadian French, Mauvaises Terres (bad lands).