Within the borders of Texas, Lake Caddo is the only natural lake. Lake Caddo was formed in the early 1800s and is the largest natural freshwater lake in the southern United States.
Lake Caddo is believed to have originated from a natural dam and the New Madrid earthquake of 1813. The surface of Lake Caddo is dotted with shallow coves as well as small inlets. Due to its size, the eastern half of this lake is located inside the border of Louisiana. Aside from Lake Caddo, Texas has many man-made lakes, such as Lake Travis, Lake Conroe and Lake Amistad.