The Mid-Continent Region of the United States is a physiographic province that extends from northern Texas and covers portions of Nebraska, Kansas and Oklahoma. This area is a transition between the Eastern Plains and drier, short grass prairies of the Great Plains Region. It is bounded by the Mississippi River on the east and the Missouri River on the west and consists of generally low-relief, flat-lying marine and stream deposits from the Mesozoic and Cenozoic Eras. Geologically, the area is tectonically stable and part of the continental core. It has been impacted by structural folding, faulting, deformation, erosion and sedimentation from the ancient, eroded mountains of the Ouachita-Ozark Highlands in the southern portion of the region. The region has significant oil and gas production in the Arbuckle, Arkoma, Nemaha Uplift, and Ouachita Mountain areas, but lacks production and has little exploration outside of these areas.