Arkansas is a state located in the southern region of the United States. Its name is an Algonquin name of the Quapaw Indians. Arkansas shares a border with six states, with its eastern border largely defined by the Mississippi River. Its diverse geography ranges from the mountainous regions of the Ozarks and the Ouachita Mountains, which make up the U.S. Interior Highlands, to the eastern lowlands along the Mississippi River. The capital and most populous city is Little Rock, located in the central portion of the state.
The name "Arkansas" derives from the same root as the name for the state of Kansas. The Kansas tribe of Native Americans are closely associated with the Sioux tribes of the Great Plains. The word "Arkansas" itself is a French pronunciation ("Arcansas") of a Quapaw (a related "Kaw" tribe) word "akakaze" meaning "land of downriver people" or the Sioux word "Akakaze" meaning "people of the south wind". The pronunciation of Arkansas was made official by an act of the state legislature in 1881, after a dispute between the two U.S. Senators from Arkansas.
In 2007, the state legislature officially declared the possessive form of the state's name to be Arkansas's.
The Mississippi River forms most of Arkansas's eastern border, except in Clay and Greene counties where the St. Francis River forms the western boundary of the Missouri Bootheel, and in dozens of places where the current channel of the Mississippi has meandered from where it had last been legally specified. Arkansas shares its southern border with Louisiana, its northern border with Missouri, its eastern border with Tennessee and Mississippi, and its western border with Texas and Oklahoma.
Arkansas is a land of mountains and valleys, thick forests and fertile plains. The so-called Lowlands are better known by names of their two regions, the Delta and the Grand Prairie. The Arkansas Delta is a flat landscape of rich alluvial soils formed by repeated flooding of the adjacent Mississippi. Further away from the river, in the southeast portion of the state, the Grand Prairie consists of a more undulating landscape. Both are fertile agricultural areas.