The Ozarks, also called the Ozark Mountains or Ozark Plateau, is a physiographic region in the U.S. states of Missouri, Arkansas, Oklahoma, and extreme southeastern Kansas. The Ozarks cover a significant portion of northern Arkansas and most of the southern half of Missouri, extending from Interstate 40 in Arkansas to Interstate 70 in central Missouri.
There are two mountain ranges within the Ozarks: the Boston Mountains of Arkansas and the St. Francois Mountains of Missouri. Buffalo Lookout, the highest point in the Ozarks, is located in the Boston Mountains. Geologically, the area is a broad dome with the exposed core in the ancient St. Francois Mountains, some of the oldest rocks in North America. The Ozarks cover nearly 47,000 square miles (120,000 km2), making it the most extensive highland region between the Appalachians and Rockies. Together with the Ouachita Mountains, the area is known as the U.S. Interior Highlands.
The Salem Plateau, named after Salem, Missouri, makes up the largest geologic area of the Ozarks. The second largest is the Springfield Plateau, named after Springfield, Missouri, nicknamed the "Queen City of the Ozarks". On the northern Ozark border are the cities of St. Louis and Columbia, Missouri. Significant cities in Arkansas include Fayetteville. Near the Missouri-Arkansas border is Branson, Missouri, a tourist destination and popularizer of Ozark culture.