Part of the Ozarks is in Arkansas.
Arkansas . The state 's diverse geography ranges from the mountainous regions of the Ozark and the Ouachita Mountains , which make up the U.S. Interior Highlands , to the densely forested land in the south known as the Arkansas Timberlands , to the eastern lowlands along the Mississippi River and the Arkansas Delta . The Ozarks , also referred to as the Ozark Mountains , Ozarks Mountain Country , and the Ozark Plateau , is a physiographic and geologic highland region of the central United States , primarily in Arkansas , Missouri , and Oklahoma . The Ozarks cover a significant portion of southern Missouri , extending as far northeast as the southwestern suburbs of St. Louis . In Arkansas , a large portion is contained within the northwestern and northcentral region .