The four-state area or quad-state area is where the states of Arkansas, Kansas, Missouri, and Oklahoma almost touch: Arkansas and Kansas share no boundary.[1][2] The metropolitan areas of Tulsa, Oklahoma; Joplin, Missouri; and Fayetteville–Springdale–Rogers, Arkansas are in the region. Notable cities and towns in the area are Tulsa and Miami, Oklahoma; Pittsburg, Kansas; Joplin, Springfield, and Monett, Missouri; and Fayetteville, Springdale, Rogers, and Bentonville, Arkansas.
The area is partially in the Ozarks. Oil and gas production and coal mining were and continue to be a large part of the region's industry. Today, a major driver of the region's economy is Walmart, the world's largest retail company, whose headquarters are in Bentonville. Also headquartered nearby in Northwest Arkansas are Tyson Foods, the world's largest processor of chicken, beef, and pork (Springdale); and major trucking and transportation company J. B. Hunt (Lowell). The city of Joplin, Missouri is nearest to the center of the four-states area.