The Chattahoochee River forms the southern half of the Alabama and Georgia border. It is a tributary of the Apalachicola River. The Chattahoochee River is about 430 miles (690 km) long.
The Chattahoochee, Flint, and Apalachicola rivers together make up the Apalachicola–Chattahoochee–Flint River Basin (ACF River Basin).