Interior Highlands is a mountainous region in the Central United States spanning northern and western Arkansas, southern Missouri, eastern Oklahoma, and southern Illinois.

[1] The name is designated by the United States Geological Survey to refer to the combined subregions of the Ouachita Mountains south of the Arkansas River and the Ozark Plateaus north of the Arkansas.

Interior Highlands is one of few mountainous regions between the Appalachians and Rockies.

Interior Highlands is dominated by temperate broadleaf and mixed forests.

Interior Highlands This Oklahoma state location article is a stub.