river having its source in several headstreams in the Blue Ridge Mountains in northeastern Georgia, U.S. It flows southwestward across northern Georgia to West Point, south of which its course marks the Georgia-Alabama and Georgia-Florida boundaries until it joins the Flint River at Chattahoochee, Fla., after a course of about 436 miles (702 km), where it forms the Apalachicola River. Northeast of Atlanta, Buford Dam forms Lake Sidney Lanier; north of Columbus, Ga., are two hydroelectric dams: Bartlett's Ferry Dam and Goat Rock Dam. The Chattahoochee is navigable from Columbus, Ga., to its mouth. South of Columbus lies the Providence Canyon area, created by severe erosion, in unconsolidated sandy soils, that has cut gullies as deep as 300 feet (90 m) and as wide as 200 feet (60 km). South of Fort Gaines, Ga., is Kolomoki Mounds State Park, developed around prehistoric Indian burial grounds. The Jim Woodruff Dam at the river's confluence with the Flint forms Lake Seminole. The name Chattahoochee is believed to be that of an early Indian village and probably means “cornmeal,” or “pounded rock.” The stream inspired Sidney Lanier's poem “The Song of the Chattahoochee.”