The Mississippi River forms the eastern boundary of Arkansas. Bearing the official nickname the "Natural State," Arkansas shares its land borders with six other states, including Mississippi, Missouri, Texas, Louisiana, Tennessee and Oklahoma.
The Mississippi River is a highly significant geographical feature in the central region of the United States and in the North American continent. The river's delta that occupies eastern Arkansas forms part of the largest alluvial plain in the country. This aquatic eco-region is surrounded by remnant marshes and broad crescent-shaped reservoirs, including the state's largest natural lake, Lake Chicot. The area is also home to a rich biodiversity and contains one of the most fertile lands in the nation.