Idaho, state in the western United States, forming the eastern section of the Pacific Northwest. Idaho is an area of striking physical diversity and natural beauty. The state's many natural resources have long been the basis of its economic output and development, and they remain a key to its future progress.
Idaho is primarily a mountainous state, much of it covered by the Rocky Mountains. High, often snowcapped peaks, broad expanses of plateaus and upland slopes, and some of the finest forestlands in the United States occupy central and northern Idaho. The mountains of the central portion of the state have long formed a barrier to communication between north and south and between east and west. North of these mountains lies a narrow section known as the Panhandle, noted for its numerous lakes and forests and abundant mineral resources.
South of the central mountains and in contrast with the rest of the state is the Snake River Plain. The plain, which is the dominant feature of southern Idaho, curves across the width of the state as a broad treeless expanse of land. It includes the most densely and most sparsely settled sections of the state. The plain includes most of the state's principal cities and accounts for much of Idaho's farm output, but it also includes some of the most desolate areas in the Pacific Northwest. Sheets of hardened lava, volcanic craters and cinder cones, and desolate crags and pinnacles form an almost totally barren landscape. Nevertheless, even these desolate areas are not without economic value, for they attract numerous tourists and contain some mineral wealth.
Idaho entered the Union on July 3, 1890, as the 43rd state. Its name was for many years popularly held to be a Native American word meaning ''gem of the mountains.'' However, some believe the name was actually coined in 1860 by white politician George M. Willing, an unsuccessful candidate for congressional delegate from the mining region of Pikes Peak in Colorado. He proposed Idaho as the name for the Colorado territory, but it was rejected when it was revealed that the name was not a Native American word. But the name took hold in the mining regions of what was to become Idaho, and the United States congress designated the territory with the name when it was formed in 1863. The popularly accepted meaning of the word Idaho gave rise to the state's nickname as the Gem State. Idaho also is known as the Potato State, after its leading crop.
