Cottonwoods line the streams, salt-loving vegetation margins the bare playas, low bushes and scattered bunch-grass grow over the lowlands, especially in the north.
The Columbia plain is for the most part treeless and, except where irrigated, grows principally bunch-grass or, in its lower and more arid parts, sagebrush.
The Great Plains are covered for the most part only with bunch grass which grows in tufts, leaving the ground visible between, and except in May and June presents a yellow and withered appearance.
Mixed with the bunch grass are occasional patches of sage brush.
The east is devoted chiefly to stock raising; for cattle, horses and sheep thrive well on the bunch grass except when it is covered with snow.