Oklahoma (abbr.: OK or Okla.), state of the United States of America, bordered on the north by Colorado and Kansas, on the east by Missouri and Arkansas, on the south by Texas, and on the west by Texas and New Mexico, 181,090 km2, with 3.1 million inhabitants; Capital: Oklahoma City.
The central part of Oklahoma lies entirely within the Osage Plains. This undulating prairie landscape gradually rises in a northwesterly direction, merging in the Panhandle into the Great Plains and foothills of the Rocky Mountains. This is where the state in Cimarron County in the far west reaches its highest point (Black Mesa, 1,517 m). To the northeast are the Ozark Mountains and to the southeast the Ouachita Mountains; both heavily forested mountain ranges are separated by the Arkansas River. The salt flats in the vicinity of Cherokee are protected as a nature reserve because of their special bird world.
Oklahoma belongs entirely to the Mississippi River Basin; all of the state’s rivers eventually flow east. The north is drained by the Arkansas. The Red River drains the south of the state. Oklahoma has no natural lakes of any size. Of the more than 200 reservoirs, especially in the east of the state, several are of considerable size, including Eufala Lake, Grand Lake O’the Cherokees and Lake Texoma. Oklahoma’s climate is influenced on the one hand by the mild climate of the Gulf of Mexico, and on the other by the continental climate of the Great Plains, and therefore has very large local differences.
The average population density is 17 inhabitants. per km2. About 68% of the population lives in urban areas. The largest cities are Oklahoma City and Tulsa. See top cities in Oklahoma.
Much of Oklahoma’s workforce is employed in agriculture. The main crop produced is wheat, followed by cotton, sorghum, corn, soybeans, groundnuts and vegetables; important are also meat production (cattle, sheep, pigs) and forestry (spruce). The industrial sector is the largest in terms of production. Petroleum refining, petrochemicals and the food industry are particularly important. The production of petroleum and natural gas is among the highest in the country. Other minerals are coal, copper and silver. The state has a number of interesting state parks, nature reserves, etc., including Great Salt Plains National Wildlife Refuge and Wichita Mountains Wildlife Refuge (including bison). The history of Oklahoma is highlighted in om
Spanish and French explorers penetrated this area in the 16th and 17th centuries, but it was not until 1824 that the first forts were built by Americans in Oklahoma, which they had acquired by purchasing Louisiana territory in 1803. The land was so arid that it was considered fit only for expelling the Native American tribes driven east of the Mississippi. Five large and relatively highly developed tribes from the south (Cherokee, Choctaws, Chickasaw, Creek and Seminoles) founded small republics with their own constitutions. Because they held slaves, they sided with the South in the American Civil War. That is why they had to give up part of their land after 1865, where other Indian tribes were also housed. In the middle of the Indian territory an open area remained, which was opened to white colonization in 1889. Soon the various reserves were also given up to the whites. The population now increased rapidly, the Indian republics amalgamated with the white settlements into a new state, which was formed on 16 Nov. 1907 as the 46th state to join the Union.