For a land-locked state, firmly entrenched on all sides by six other states, Oklahoma is a stunning dichotomy of diverse terrain, people and history. Within almost 70,000 square miles of land, the state of Oklahoma has more man-made lakes than any other state and 2,000 more miles of shoreline than the Atlantic and Gulf coasts combined. There are four mountain ranges including the Quachitas, Arbuckles, Wichitas and Kiamichis. Forests cover approximately 24% of the state. Oklahoma cities such as the populous capital Oklahoma City and the other large metropolitan areas of Tulsa, Norman and Lawton are an affirmation of Oklahoma's Western heritage. While they are host to all the modern amenities of a fast-growing, future-thinking city, numerous science and history museums, cultural events and monuments preserve the fabric of history unique to each area of Oklahoma. Oklahoma is one of the six states on the Frontier Strip. It is bounded on the east by Arkansas and Missouri, on the north by Kansas and northwest by Colorado (both at 37°N), on the far west by New Mexico (at 103°W), and on the south and near-west by Texas. The panhandle's southern boundary is at 36.5°N, then turning due south along 100°W to the southern fork of the Red River), completing the round trip back to Arkansas. Oklahoma's four main mountain ranges include the Ouachitas, Arbuckles, Wichitas, and the Kiamichis. In addition to several smaller ranges, Oklahoma also notably encompasses a portion of the Ozarks. The state's highest peak, 4,973 feet Black Mesa, resides in the far northwestern corner of the panhandle near the town of Kenton. The lowest elevation in the state is in the far southeastern corner, near Idabel, at 324 feet. Oklahoma also has what is officially considered the highest hill in the world, Cavanal Hill, at 1,999 feet this is considering the fact that a "mountain" is anything 2,000 feet or higher. It is located in Poteau, Oklahoma. With 200 man-made lakes, Oklahoma has more man-made lakes than any other state and boasts over one million surface-acres of water and 2,000 more miles of shoreline than the Atlantic and Gulf coasts combined. Lake Eufaula is the largest lake in the state, covering 102,000 surface acres of water. Oklahoma is recognized by the EPA as having 11 different ecoregions (one of only four U.S. states to have more than 10 ecoregions). These ecoregions are: Western high plains, Southwestern Tablelands, Central Great Plains, Tall Grass Prairie, Cross Timbers, Caves & Prairie, Ozark Highlands, Ozark Forest, Hardwood Forest, Ouachita Mountains, and Cypress Swamps & Forests. The Oklahoma Tourism Department divides the state down into six "countries" for tourism promotion purposes: Red Carpet Country (Northwestern Oklahoma and The Panhandle), Great Plains Country (Southwestern Oklahoma), Frontier Country (Central Oklahoma, including the Oklahoma City Metropolitan area), Green Country (Northeastern Oklahoma, including the Tulsa Metropolitan area), Kiamichi country (Southeastern Oklahoma), and Lake & Trail Country (South Central Oklahoma). Popular but "unofficial" regional designations include Green Country (most often used to refer to Northeastern Oklahoma, but used by some to refer to either all of Eastern Oklahoma or just the Tulsa Metropolitan Area), Little Dixie (Southeastern Oklahoma), Western Oklahoma, and the Oklahoma Panhandle.