region in the United States, comprising the southern portion of the Great Plains, or, in its most specific sense, the northern portion of the Llano Estacado (“Staked Plain”). In the latter sense, the High Plains may be said to cover the northernmost Panhandle of Texas, northeastern New Mexico, eastern Colorado, and westernmost Kansas. The High Plains are generally flat grassland, drained eastward by the Platte, Arkansas, and Canadian rivers. The economy is based on cattle, irrigated and dry farming, and some natural-gas and petroleum extraction.