The Ozarks are a set of highlands located midway between the Appalachian Mountains and the Rocky Mountains. In fact, it is the largest highland area between the aforementioned two massive mountain ranges, and it is found in the middle of a lowland area. Regionally speaking, the Ozarks are located in the Southern region of the United States.
These highlands are not in the same category as the large mountain ranges in the east and west of the United States. Instead, they are relatively low in elevation, with more plateau-like features, and the area they occupy is also relatively small when compared to large mountain ranges. Anyhow, because it is located in the middle of a vast lowland area, it sticks out from its surroundings and seems much more marking and high than what it actually is.
There are three main sources of heat in the deep earth: (1) heat from when the planet formed and accreted, which has not yet been lost; (2) frictional heating, caused by denser core material sinking to the center of the planet; and (3) heat from the decay of radioactive elements.