Missouri Plateau

a plateau in the USA and Canada, the central part of the Great Plains in the Missouri basin. It is composed of Paleocene and Neocene sedimentary rock, mostly sandstone. The surface is flat and slopes from west to east. From 1,600 m at the foot of the Rockies the plateau descends to 500 m along its eastern edge. In places, groups of mountains, such as the Black Hills and Big Snowy Mountains, rise to 2,200 m. The plateau is composed chiefly of sandstone; in the north it is covered with glacial deposits. Along the valleys of large rivers, it is dissected by many ravines, which in places form badlands. It has an arid continental climate. Chernozems predominate in the east and chestnut soils in the west. The natural vegetation is feather grass and forb steppe in the east and dry grama and forb steppe at the foot of the Rockies.