Great Plains

Semi-arid region of about 3.2 million sq km/1.2 million sq mi in North America, to the east of the Rocky Mountains, stretching as far as the 100th meridian of longitude through Oklahoma, Kansas, Nebraska, and the Dakotas. The Plains, which cover one-fifth of the USA, extend from Texas in the south over 2,400 km/1,500 mi north to Alberta, Saskatchewan, and Manitoba in Canada, where they are known as the Prairies. The Great Plains have extensive oil and coal reserves, many of which are actively worked. Ranching and wheat farming have resulted in overuse of the water resources, and the consequent process of erosion has reduced available farmland. Around 15 million people live on the Great Plains.

Before the arrival of the Spanish in the 16th century, few people lived on the Plains; the scattered groups that were there lived mainly in the bottomlands of the major rivers. The arrival of the horse, however, gave birth to a completely new culture, made up of peoples from many places, such as the Sioux, who were pushed southwest from Minnesota. Known as the Plains Indians, they used the horse to expand their buffalo hunts across the wide open spaces of the Great Plains.

In 1823 a US government surveyor named the region the Great American Desert, an unfortunate title that led settlers to believe that the land was unsuitable for cultivation. Also, the majority of the Plains inhabitants were American Indians, and were ready to defend their homelands. However, by the middle of the 19th century the more fertile lands of California and Oregon had been taken, so US settlers had to look for other land and, as predicted, they targeted the Great Plains. Most of the Indian battles of the period 1850–1900, known as the Plains Wars, occurred here. Despite the fighting, a combination of the Homestead Act (1862) and the promotional efforts of the Transcontinental Railroad companies brought a great many homesteaders to the area, including Europeans who introduced winter wheat and other agricultural innovations to the farming communities. About 25% of the world's wheat, oats, barley, rye, sorghum, and corn are produced in the region.

Settlement had slowed by the early 20th century, as the frontier closed. The ploughing of the short-grass prairie was increased to meet European food shortages during World War I, resulting in dust bowl conditions during the 1930s. Developments in farming techniques and irrigation have kept that disaster from happening again but the area must now deal with a constantly decreasing ground water supply. Large-scale agribusinesses have made it difficult, if not impossible, for the family farm to function, so people are continuing to leave the rural areas, just as they did in the 1930's Depression. However, improvements in commuting and work in information technology have attracted people to the region. The Great Plains Buffalo (or bison) is gradually being reintroduced.