The Ouachita Mountains (/ˈwɒʃɨtɔː/ WOSH-i-taw) are a mountain range in west central Arkansas and southeastern Oklahoma. The range's subterranean roots may extend as far as central Texas, or beyond it to the current location of the Marathon Uplift. Along with the Ozark Mountains, the Ouachita Mountains form the U.S. Interior Highlands, one of the few major mountainous regions between the Rocky Mountains and the Appalachian Mountains.