New River, c.320 mi (510 km) long, rising in the Blue Ridge, NW N.C. It flows NE through SW Virginia, then NW into West Virginia where it joins with the Gauley River to form the Kanawha River. It is used extensively to generate electricity. Bluestone Dam (completed 1952), near Hinton, W.Va., provides flood control and power, and its reservoir extends 36 mi (58 km) upstream. The New River Bridge, built across the River Gorge, is the largest steel-arch bridge in the United States.