Alabama is in the southeastern part of the United States, between Mississippi to the west and Georgia and Florida to the east. Most of Alabama’s southern border adjoins Florida, but a small portion of the state extends down to the Gulf of Mexico. The northern part of Alabama, just below Tennessee, is known as the Appalachian region. It is made up of high plateaus, ridges, valleys, and the high Talladega Mountains. The Piedmont Plateau, another rocky region, extends from the Talladega Mountains to the Georgia border. Until well into the twentieth century, many of the people in the highlands of Alabama lived the isolated lives of mountain and hill dwellers. The Interior Low Plateau region is the part of northern Alabama drained by the Tennessee River. Below the northern uplands, the Gulf Coastal Plains extend south to the Gulf of Mexico. The Gulf Coastal Plains include the Black Belt, a dark-soiled prairie.