Geography of Oklahoma The Geography of Oklahoma encompasses terrain and ecosystems ranging from arid plains to subtropical forests and mountains. Oklahoma contains 10 distinct ecological regions, more per square mile than in any other state by a wide margin. It is situated in the Great Plains and U.S. Interior Highlands region near the geographical center of the 48 contiguous states. Usually considered part of the South Central United States, Oklahoma is bounded on the east by Arkansas and Missouri, on the north by Kansas, on the northwest by Colorado, on the far west by New Mexico, and on the south
and with 200 lakes created by dams, it holds the highest number of reservoirs in the nation. Oklahoma covers an area of , with of land and of water, making it the 20th-largest state in the United States. Generally, it is divided into seven geographical regions: Green Country, or Northeast Oklahoma, Southeastern Oklahoma, Central Oklahoma, South Central Oklahoma, Southwest Oklahoma, Northwest Oklahoma, and the Oklahoma Panhandle. Situated between the Great Plains and the Ozark Plateau in the Gulf of Mexico watershed, Oklahoma tends to slope gradually downward from its western to eastern boundaries. Its highest and lowest points follow this
200 lakes created by dams, it holds the nation's highest number of artificial reservoirs. Most of the state lies in two primary drainage basins belonging to the Red and Arkansas rivers, though the Lee and Little rivers also contain significant drainage basins. Due to Oklahoma's location at the confluence of many geographic regions, the state's climatic regions have a high rate of biodiversity. Forests cover 24 percent of Oklahoma and prairie grasslands composed of shortgrass, mixed-grass, and tallgrass prairie, harbor expansive ecosystems in the state's central and western portions, although cropland has largely replaced native grasses. Where rainfall is sparse
in Norman. Winter and spring weather often are influenced by the El Niño Southern Oscillation. Winters during El Niño are cooler than average and wetter across the western portion of the state due to an amplified southern jet stream. During La Niña, the storm track is further north, therefore winters are warmer than average and drier in the western part of the state. Geography of Oklahoma The Geography of Oklahoma encompasses terrain and ecosystems ranging from arid plains to subtropical forests and mountains. Oklahoma contains 10 distinct ecological regions, more per square mile than in any other state by a
Southwestern Oklahoma Southwest Oklahoma is a geographical name for the southwest portion of the state of Oklahoma, typically considered to be south of the Canadian River, extending eastward from the Texas border to a line roughly from Weatherford, to Anadarko, to Duncan. Geologically, the region is defined by a failed continental rift known as the Southern Oklahoma Aulacogen. The austere nature of the prairie landscape with intermittent island ranges has made it a favorable place for artists and photographers alike. Anchored by Lawton, its largest city, Southwest Oklahoma's other important urban centers include Elk City, Clinton, Weatherford, Walters, Altus, and
Oklahoma 's 10 geographic regions are defined by surface features called?

Reference answer:
ecological regions