The folds and the mountains trend east-west. Mixed forest of the Ouachita Mountains, Hot Springs, Arkansas. Winters are warm and summers hot.
Rain falls throughout the year, but summers are relatively dry.
The primary overstory species are southern red oak, black oak, white oak, and hickories. The dry sandstone ridges of the Ouachita Mountains are covered on their southern slopes by a mixture of shortleaf pine, oak, and hickory, and on their northern slopes by hardwood forests made up mainly of oak and hickory. Hardwoods populate the rich bottom lands of the valleys, and pines predominate on poorer lands. They are stony and nonstony, with medium textures. One amphibian, the Ouachita dusky salamander, is found exclusively in this province's rocky, gravelly streams.