The Fore River is a short horn-shaped estuary, approximately 5.7 miles (9.2 km) long, separating Portland and South Portland in Maine in the United States. Many of the port facilities of the Portland harbor are along the estuary, which is formed just southwest of Portland by the confluence of several creeks. The estuary was initially known as Levett's River, so named by the first English settler of the Casco Bay region, Capt. Christopher Levett.