The natural boundary that separates Tennessee and Arkansas is the Mississippi River. This iconic river flows along the eastern side of Arkansas and the western side of Tennessee, serving as a prominent geographical divide between the two states.
The Mississippi River is not only significant due to its size and length but also plays a vital role in the ecology, history, and economy of the region. It has historically served as a major transportation route and is crucial for local wildlife and habitats, making it an essential part of the landscape that defines the border between these two states.