ITYDROGRAPHY. The greater part of the State's surface is drained directly into the Atlantic or its great arm, Chesapeake Bay. The largest river within the State is the James, which rises on the western boundary. breaks through the Blue Ridge, and enters the foot of Chesapeake Bay through a large tidal estuary. All of the rivers flowing into Chesapeake Bay enter it through estuaries which are very large for the size of the stream, such as the York River, the common estuary of the Pamunkey and Matta pony. the estuary of the Rappahannock. and, greatest of all, that of the Potomac on the northeastern boundary. All the rivers east of the Blue Ridge flow in parallel southen stward courses, and those traversing the southern part of the Piedmont Plain, chief of which is the Staunton, flow across the boundary into North Carolina. The Great Valley and Appalachian region are drained by several river systems. Through the northern part of the valley
flows the Shenandoah to join the Potomac. while the central valley and mountain region are wa tered by the upper course of the James and its trilnit pries. Farther south the New River or Great Kanawha traverses the mountain belt and pusses into West Virginia on its we to the Ohio, while the southwestern part of the State gives rise to the headstreams of the Tennessee River. The deep and wide estuaries of the east ern rivers admit large vessels to the heart of the State, hut a short distance above the heads of the estuaries navigation is blocked on all the rivers at the Fall Line, where the streams fall over the escarpment of the Piedmont Plain. The only lake in Virginia is Drummond Lake, situ ated in the centre of the Dismal Swamp (q.v.), in the southeastern corner of the State.