Ozark Plateau

The Ozark Plateau—also called the Ozark Mountains, Ozark Highlands, or simply the Ozarks—is a large highland region spanning Missouri, Arkansas, Oklahoma, and a sliver of southeastern Kansas. It covers roughly 47,000 square miles, making it the most extensive upland area between the Appalachian and Rocky Mountains. Together with the Ouachita Mountains, it forms the U.S. Interior Highlands.

The region’s highest point is Wahzhazhe Summit (formerly Buffalo Lookout) in the Boston Mountains of western Newton County, Arkansas, reaching 2,561 feet. Two distinct mountain ranges exist within the Ozarks: the Boston Mountains in Arkansas and Oklahoma, and the St. Francois Mountains in Missouri. Geologically, the Ozarks are a broad dome, with the ancient St. Francois Mountains forming its exposed core.

The Salem Plateau, named after Salem, Missouri, is the largest geologic subdivision, followed by the Springfield Plateau, named after Springfield, Missouri—often called the "Queen City of the Ozarks." Major cities on the northern edge include St. Louis and Jefferson City, Missouri. In Arkansas, significant Ozark towns are Fayetteville, Springdale, Rogers, Bentonville, Harrison, Mountain Home, Batesville, and Eureka Springs. Branson, Missouri, just north of the Arkansas border, is a popular tourist hub where Ozark culture is widely promoted.

The name "Ozarks" has uncertain origins. It may come from an English adaptation of the French abbreviation *aux Arcs*, short for *aux Arcansas*, meaning "of/at/to the Arkansas (Quapaw) people." Before the French and Indian War (1754–1763), *aux Arkansas* referred to France’s trading post at Arkansas Post, in the wooded Arkansas Delta near the Arkansas River’s confluence with the Mississippi. Another possible source is the French phrase *aux arcs*, meaning "[land] of the arches," referencing natural bridges formed by erosion and collapsed caves, such as Clifty Hollow Natural Bridge in Missouri and Alum Cove in the Ozark–St. Francis National Forest. By the early 1900s, "Ozarks" was common in everyday speech.

The Ozarks are divided into several physiographic subregions: the Boston Mountains (north Arkansas) and Cookson Hills (east Oklahoma); the Springfield Plateau (southwest Missouri, northeast Oklahoma, northwest Arkansas, and southeast Kansas), which includes towns like Springfield, Joplin, and Monett/Aurora in Missouri, Tahlequah in Oklahoma, Fayetteville and Harrison in Arkansas, and Galena in Kansas; the White River Hills along the White River, including Branson, Mountain Home, and Batesville; the Salem Plateau (a broad band across south-central Missouri and north-central Arkansas, covering Lebanon, Salem, and West Plains); the Courtois Hills of southeastern Missouri; the Osage-Gasconade Hills around the Lake of the Ozarks; the Saint Francois Mountains; and the Missouri and Mississippi River border areas along the eastern and northeastern edges.

Karst features—springs, losing streams, sinkholes, and caves—are common in the limestone of the Springfield Plateau and abundant in the dolomite bedrock of the Salem Plateau and Boston Mountains. Missouri, known as "The Cave State," has over 7,300 recorded caves, second only to Tennessee, with most in Ozark counties. The Ozark Plateaus aquifer system governs groundwater movement everywhere except the igneous core of the St. Francois Mountains. Geographic highlights include limestone and dolomite glades—rocky, desert-like hilltops kept open by periodic fires that limit grass and forb growth in shallow soil. These glades host collared lizards, tarantulas, scorpions, cacti, and other species typical of the Desert Southwest.

The Boston Mountains have the highest elevations in the Ozarks, with peaks over 2,500 feet, and some of the greatest relief between the Appalachians and Rockies. (The Ouachita Mountains to the south are slightly higher but not part of the Ozarks.) This portion extends 20 to 35 miles north of the Arkansas River Valley, is about 200 miles long, and is bordered by the Springfield and Salem Plateaus north of the White River. Summits can exceed 2,560 feet, with valleys 500 to 1,550 feet deep. Turner Ward Knob, at 2,463 feet, is the highest named peak, located in western Newton County, Arkansas; five unnamed nearby peaks reach or slightly exceed 2,560 feet. Drainage flows mainly to the White River, except for the Illinois River, though south slopes of the Boston Mountains also drain to the Arkansas River via streams like Lee Creek, Frog Bayou, Mulberry River, Spadra Creek, Big Piney Creek, Little Piney Creek, Illinois Bayou, Point Remove Creek, and Cadron Creek. Many Ozark waterways—including the Buffalo, Kings, Mulberry, Little Red, and White rivers—begin in the Boston formation’s uplands.

Topography is mostly gently rolling on the Springfield and Salem plateaus, while the Saint Francois Mountains are more rugged. The Springfield formation’s surface is primarily Mississippian limestone.