The United States Interior Highlands, commonly called Interior Highlands is a mountainous region in the Central United States, particularly in the states of Arkansas, Oklahoma, Missouri, Kansas and Texas. This Interior Highlands region can be separated into at least three separate areas, which are called the Ozark Highlands, Ouachita Mountains and the Wichita Mountain.

The Interior Highlands is one of the very few mountainous regions between the Appalachians and Rockies, and it covers a somewhat large areas of these interior states, making it the most extensive highland region between the Appalachians and Rockies.

The name, Interior Highlands, is designated by the United States Geological Survey to refer to the combined subregions of the Ouachita Mountains and the Ozark Mountains. Due to the nearness of the Wichita Mountains, I have included these in my definition of Interior Highlands.

The Interior Highlands are a broad dome with the exposed core in the St. Francois Mountains. The exposed core area has most likely become exposed due to the erosion of the sedimentary rock over-cover by the nearby rivers, primarily the Mississippi and Missouri rivers.

Further, the area between the Boston Mountains and the Ouachita Mountains is the Arkansas river valley which also most likely eroded through the mountainous area of the Interior Highlands.

Although those who study Geology claim that the Interior Highlands, specifically the Springfield plateau extends into the southeast corner of Kansas, I have yet to find any significant indication of the Ozark highlands in this area.

Maybe this claim is because the area has an elevation of about 1000 feet which drops off very quickly the further into Kansas one travels from the southeast corner.

Like Kansas, those who study geology claim that the eastern part of the northern panhandle has some of the mountains which are part of the Interior Highlands. As yet, I have not been able to find these mountains, but I will most likely keep looking in future visits.

Too, like what I have heard from some studies, often, the traces of very old mountains have, over the course of millions of years, sometimes been over-covered by sedimentary rock and this is most likely the case with the Wichita mountains that are in Texas.